chrislu
2 months ago
4 changed files with 101 additions and 380 deletions
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30weed/server/postgres/README.md
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85weed/server/postgres/protocol.go
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10weed/server/postgres/server.go
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356weed/server/postgres/translator.go
@ -1,356 +0,0 @@ |
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package postgres |
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|
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import ( |
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"fmt" |
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"regexp" |
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"strings" |
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) |
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|
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// PostgreSQL to SeaweedFS SQL translator
|
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type PostgreSQLTranslator struct { |
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systemQueries map[string]string |
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patterns map[*regexp.Regexp]string |
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} |
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|
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// initSystemQueries initializes the system query mappings
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func (t *PostgreSQLTranslator) initSystemQueries() { |
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t.systemQueries = map[string]string{ |
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// Version queries
|
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"SELECT version()": "SELECT 'SeaweedFS 1.0 (PostgreSQL 14.0 compatible)' as version", |
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"SELECT version() AS version": "SELECT 'SeaweedFS 1.0 (PostgreSQL 14.0 compatible)' as version", |
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"select version()": "SELECT 'SeaweedFS 1.0 (PostgreSQL 14.0 compatible)' as version", |
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|
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// Current database
|
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"SELECT current_database()": "SELECT 'default' as current_database", |
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"select current_database()": "SELECT 'default' as current_database", |
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"SELECT current_database() AS current_database": "SELECT 'default' as current_database", |
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|
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// Current user
|
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"SELECT current_user": "SELECT 'seaweedfs' as current_user", |
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"select current_user": "SELECT 'seaweedfs' as current_user", |
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"SELECT current_user AS current_user": "SELECT 'seaweedfs' as current_user", |
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"SELECT user": "SELECT 'seaweedfs' as user", |
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|
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// Session info
|
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"SELECT session_user": "SELECT 'seaweedfs' as session_user", |
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"SELECT current_setting('server_version')": "SELECT '14.0' as server_version", |
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"SELECT current_setting('server_encoding')": "SELECT 'UTF8' as server_encoding", |
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"SELECT current_setting('client_encoding')": "SELECT 'UTF8' as client_encoding", |
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|
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// Simple system queries
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"SELECT 1": "SELECT 1", |
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"select 1": "SELECT 1", |
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"SELECT 1 AS test": "SELECT 1 AS test", |
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|
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// Database listing
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"SELECT datname FROM pg_database": "SHOW DATABASES", |
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"SELECT datname FROM pg_database ORDER BY datname": "SHOW DATABASES", |
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|
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// Table listing
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"SELECT tablename FROM pg_tables": "SHOW TABLES", |
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"SELECT schemaname, tablename FROM pg_tables": "SHOW TABLES", |
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"SELECT table_name FROM information_schema.tables": "SHOW TABLES", |
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"SELECT table_name FROM information_schema.tables WHERE table_schema = 'public'": "SHOW TABLES", |
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|
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// Schema queries
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"SELECT schema_name FROM information_schema.schemata": "SELECT 'public' as schema_name", |
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"SELECT nspname FROM pg_namespace": "SELECT 'public' as nspname", |
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|
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// Connection info
|
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"SELECT inet_client_addr()": "SELECT '127.0.0.1' as inet_client_addr", |
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"SELECT inet_client_port()": "SELECT 0 as inet_client_port", |
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"SELECT pg_backend_pid()": "SELECT 1 as pg_backend_pid", |
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|
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// Transaction info
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"SELECT txid_current()": "SELECT 1 as txid_current", |
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"SELECT pg_is_in_recovery()": "SELECT false as pg_is_in_recovery", |
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|
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// Statistics
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"SELECT COUNT(*) FROM pg_stat_user_tables": "SELECT 0 as count", |
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|
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// Empty system tables
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"SELECT * FROM pg_settings LIMIT 0": "SELECT 'name' as name, 'setting' as setting, 'unit' as unit, 'category' as category, 'short_desc' as short_desc, 'extra_desc' as extra_desc, 'context' as context, 'vartype' as vartype, 'source' as source, 'min_val' as min_val, 'max_val' as max_val, 'enumvals' as enumvals, 'boot_val' as boot_val, 'reset_val' as reset_val, 'sourcefile' as sourcefile, 'sourceline' as sourceline, 'pending_restart' as pending_restart WHERE 1=0", |
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|
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"SELECT * FROM pg_type LIMIT 0": "SELECT 'oid' as oid, 'typname' as typname, 'typlen' as typlen WHERE 1=0", |
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|
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"SELECT * FROM pg_class LIMIT 0": "SELECT 'oid' as oid, 'relname' as relname, 'relkind' as relkind WHERE 1=0", |
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} |
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|
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// Initialize regex patterns for more complex queries
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t.patterns = map[*regexp.Regexp]string{ |
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// \d commands (psql describe commands)
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regexp.MustCompile(`(?i)\\d\+?\s*$`): "SHOW TABLES", |
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regexp.MustCompile(`(?i)\\dt\+?\s*$`): "SHOW TABLES", |
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regexp.MustCompile(`(?i)\\dn\+?\s*$`): "SELECT 'public' as name, 'seaweedfs' as owner", |
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regexp.MustCompile(`(?i)\\l\+?\s*$`): "SHOW DATABASES", |
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regexp.MustCompile(`(?i)\\d\+?\s+(\w+)$`): "DESCRIBE $1", |
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regexp.MustCompile(`(?i)\\dt\+?\s+(\w+)$`): "DESCRIBE $1", |
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|
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// pg_catalog queries
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regexp.MustCompile(`(?i)SELECT\s+.*\s+FROM\s+pg_catalog\.pg_tables`): "SHOW TABLES", |
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regexp.MustCompile(`(?i)SELECT\s+.*\s+FROM\s+pg_tables`): "SHOW TABLES", |
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regexp.MustCompile(`(?i)SELECT\s+.*\s+FROM\s+pg_database`): "SHOW DATABASES", |
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|
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// SHOW commands (already supported but normalize)
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regexp.MustCompile(`(?i)SHOW\s+DATABASES?\s*;?\s*$`): "SHOW DATABASES", |
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regexp.MustCompile(`(?i)SHOW\s+TABLES?\s*;?\s*$`): "SHOW TABLES", |
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regexp.MustCompile(`(?i)SHOW\s+SCHEMAS?\s*;?\s*$`): "SELECT 'public' as schema_name", |
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|
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// BEGIN/COMMIT/ROLLBACK (no-op for read-only)
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regexp.MustCompile(`(?i)BEGIN\s*;?\s*$`): "SELECT 'BEGIN' as status", |
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regexp.MustCompile(`(?i)START\s+TRANSACTION\s*;?\s*$`): "SELECT 'BEGIN' as status", |
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regexp.MustCompile(`(?i)COMMIT\s*;?\s*$`): "SELECT 'COMMIT' as status", |
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regexp.MustCompile(`(?i)ROLLBACK\s*;?\s*$`): "SELECT 'ROLLBACK' as status", |
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// SET commands (mostly no-op)
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regexp.MustCompile(`(?i)SET\s+.*\s*;?\s*$`): "SELECT 'SET' as status", |
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|
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// Column information queries
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regexp.MustCompile(`(?i)SELECT\s+.*\s+FROM\s+information_schema\.columns\s+WHERE\s+table_name\s*=\s*'(\w+)'`): "DESCRIBE $1", |
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} |
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} |
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|
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// TranslateQuery translates a PostgreSQL query to SeaweedFS SQL
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func (t *PostgreSQLTranslator) TranslateQuery(pgSQL string) (string, error) { |
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// Trim whitespace and semicolons
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query := strings.TrimSpace(pgSQL) |
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query = strings.TrimSuffix(query, ";") |
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|
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// Check for exact matches first
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if seaweedSQL, exists := t.systemQueries[query]; exists { |
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return seaweedSQL, nil |
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} |
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|
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// Check case-insensitive exact matches
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queryLower := strings.ToLower(query) |
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for pgQuery, seaweedSQL := range t.systemQueries { |
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if strings.ToLower(pgQuery) == queryLower { |
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return seaweedSQL, nil |
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} |
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} |
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|
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// Check regex patterns
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for pattern, replacement := range t.patterns { |
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if pattern.MatchString(query) { |
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// Handle replacements with capture groups
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if strings.Contains(replacement, "$") { |
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return pattern.ReplaceAllString(query, replacement), nil |
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} |
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return replacement, nil |
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} |
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} |
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|
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// Handle psql meta-commands
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if strings.HasPrefix(query, "\\") { |
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return t.translateMetaCommand(query) |
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} |
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|
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// Handle information_schema queries
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if strings.Contains(strings.ToLower(query), "information_schema") { |
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return t.translateInformationSchema(query) |
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} |
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|
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// Handle pg_catalog queries
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if strings.Contains(strings.ToLower(query), "pg_catalog") || strings.Contains(strings.ToLower(query), "pg_") { |
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return t.translatePgCatalog(query) |
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} |
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|
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// For regular queries, pass through as-is
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// The SeaweedFS SQL engine will handle standard SQL
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return query, nil |
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} |
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|
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// translateMetaCommand translates psql meta-commands
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func (t *PostgreSQLTranslator) translateMetaCommand(cmd string) (string, error) { |
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cmd = strings.TrimSpace(cmd) |
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|
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switch { |
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case cmd == "\\d" || cmd == "\\dt": |
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return "SHOW TABLES", nil |
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case cmd == "\\l": |
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return "SHOW DATABASES", nil |
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case cmd == "\\dn": |
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return "SELECT 'public' as schema_name, 'seaweedfs' as owner", nil |
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case cmd == "\\du": |
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return "SELECT 'seaweedfs' as rolname, true as rolsuper, true as rolcreaterole, true as rolcreatedb", nil |
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case strings.HasPrefix(cmd, "\\d "): |
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// Describe table
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tableName := strings.TrimSpace(cmd[3:]) |
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return fmt.Sprintf("DESCRIBE %s", tableName), nil |
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case strings.HasPrefix(cmd, "\\dt "): |
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// Describe table (table-specific)
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tableName := strings.TrimSpace(cmd[4:]) |
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return fmt.Sprintf("DESCRIBE %s", tableName), nil |
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case cmd == "\\q": |
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return "SELECT 'quit' as status", fmt.Errorf("client requested quit") |
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case cmd == "\\h" || cmd == "\\help": |
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return "SELECT 'SeaweedFS PostgreSQL Interface - Limited command support' as help", nil |
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case cmd == "\\?": |
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return "SELECT 'Available: \\d (tables), \\l (databases), \\q (quit)' as commands", nil |
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default: |
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return "SELECT 'Unsupported meta-command' as error", fmt.Errorf("unsupported meta-command: %s", cmd) |
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} |
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} |
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|
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// translateInformationSchema translates INFORMATION_SCHEMA queries
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func (t *PostgreSQLTranslator) translateInformationSchema(query string) (string, error) { |
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queryLower := strings.ToLower(query) |
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if strings.Contains(queryLower, "information_schema.tables") { |
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return "SHOW TABLES", nil |
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} |
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if strings.Contains(queryLower, "information_schema.columns") { |
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// Extract table name if present
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re := regexp.MustCompile(`(?i)table_name\s*=\s*'(\w+)'`) |
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matches := re.FindStringSubmatch(query) |
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if len(matches) > 1 { |
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return fmt.Sprintf("DESCRIBE %s", matches[1]), nil |
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} |
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return "SHOW TABLES", nil // Return tables if no specific table
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} |
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|
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if strings.Contains(queryLower, "information_schema.schemata") { |
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return "SELECT 'public' as schema_name, 'seaweedfs' as schema_owner", nil |
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} |
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|
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// Default fallback
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return "SELECT 'information_schema query not supported' as error", nil |
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} |
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|
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// translatePgCatalog translates PostgreSQL catalog queries
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func (t *PostgreSQLTranslator) translatePgCatalog(query string) (string, error) { |
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queryLower := strings.ToLower(query) |
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|
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// pg_tables
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if strings.Contains(queryLower, "pg_tables") { |
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return "SHOW TABLES", nil |
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} |
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|
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// pg_database
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if strings.Contains(queryLower, "pg_database") { |
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return "SHOW DATABASES", nil |
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} |
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|
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// pg_namespace
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if strings.Contains(queryLower, "pg_namespace") { |
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return "SELECT 'public' as nspname, 2200 as oid", nil |
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} |
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|
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// pg_class (tables, indexes, etc.)
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if strings.Contains(queryLower, "pg_class") { |
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return "SHOW TABLES", nil |
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} |
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|
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// pg_type (data types)
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if strings.Contains(queryLower, "pg_type") { |
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return t.generatePgTypeResult(), nil |
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} |
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|
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// pg_attribute (column info)
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if strings.Contains(queryLower, "pg_attribute") { |
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return "SELECT 'attname' as attname, 'atttypid' as atttypid, 'attnum' as attnum WHERE 1=0", nil |
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} |
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|
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// pg_settings
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if strings.Contains(queryLower, "pg_settings") { |
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return t.generatePgSettingsResult(), nil |
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} |
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|
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// pg_stat_* tables
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if strings.Contains(queryLower, "pg_stat_") { |
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return "SELECT 0 as count", nil |
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} |
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|
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// Default: return empty result for unknown pg_ queries
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return "SELECT 'pg_catalog query not fully supported' as notice", nil |
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} |
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|
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// generatePgTypeResult generates a basic pg_type result
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func (t *PostgreSQLTranslator) generatePgTypeResult() string { |
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return ` |
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SELECT * FROM ( |
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SELECT 16 as oid, 'bool' as typname, 1 as typlen, 'b' as typtype |
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UNION ALL |
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SELECT 20 as oid, 'int8' as typname, 8 as typlen, 'b' as typtype |
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UNION ALL |
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SELECT 23 as oid, 'int4' as typname, 4 as typlen, 'b' as typtype |
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UNION ALL |
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SELECT 25 as oid, 'text' as typname, -1 as typlen, 'b' as typtype |
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UNION ALL |
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SELECT 701 as oid, 'float8' as typname, 8 as typlen, 'b' as typtype |
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UNION ALL |
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SELECT 1043 as oid, 'varchar' as typname, -1 as typlen, 'b' as typtype |
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UNION ALL |
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SELECT 1114 as oid, 'timestamp' as typname, 8 as typlen, 'b' as typtype |
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) t WHERE 1=0 |
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` |
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} |
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|
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// generatePgSettingsResult generates a basic pg_settings result
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func (t *PostgreSQLTranslator) generatePgSettingsResult() string { |
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return ` |
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SELECT * FROM ( |
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SELECT 'server_version' as name, '14.0' as setting, NULL as unit, 'Version and Platform Compatibility' as category, 'SeaweedFS version' as short_desc |
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UNION ALL |
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SELECT 'server_encoding' as name, 'UTF8' as setting, NULL as unit, 'Client Connection Defaults' as category, 'Server encoding' as short_desc |
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UNION ALL |
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SELECT 'client_encoding' as name, 'UTF8' as setting, NULL as unit, 'Client Connection Defaults' as category, 'Client encoding' as short_desc |
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UNION ALL |
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SELECT 'max_connections' as name, '100' as setting, NULL as unit, 'Connections and Authentication' as category, 'Maximum connections' as short_desc |
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) s WHERE 1=0 |
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` |
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} |
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|
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// GetDatabaseName returns the appropriate database name for the session
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func (t *PostgreSQLTranslator) GetDatabaseName(requestedDB string) string { |
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if requestedDB == "" || requestedDB == "postgres" || requestedDB == "template1" { |
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return "default" |
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} |
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return requestedDB |
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} |
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|
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// IsSystemQuery checks if a query is a system/meta query that doesn't access actual data
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func (t *PostgreSQLTranslator) IsSystemQuery(query string) bool { |
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queryLower := strings.ToLower(strings.TrimSpace(query)) |
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|
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// System function calls
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systemFunctions := []string{ |
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"version()", "current_database()", "current_user", "session_user", |
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"current_setting(", "inet_client_", "pg_backend_pid()", "txid_current()", |
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"pg_is_in_recovery()", |
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} |
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|
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for _, fn := range systemFunctions { |
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if strings.Contains(queryLower, fn) { |
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return true |
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} |
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} |
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|
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// System table queries
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systemTables := []string{ |
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"pg_catalog", "pg_tables", "pg_database", "pg_namespace", "pg_class", |
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"pg_type", "pg_attribute", "pg_settings", "pg_stat_", "information_schema", |
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} |
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|
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for _, table := range systemTables { |
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if strings.Contains(queryLower, table) { |
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return true |
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} |
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} |
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|
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// Meta commands
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if strings.HasPrefix(queryLower, "\\") { |
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return true |
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} |
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|
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// Transaction control
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transactionCommands := []string{"begin", "commit", "rollback", "start transaction", "set "} |
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for _, cmd := range transactionCommands { |
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if strings.HasPrefix(queryLower, cmd) { |
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return true |
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} |
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} |
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|
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return false |
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} |
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