postgresql-syntax-reference

Understand PostgreSQL SQL syntax and parsing rules to implement and validate DDL parsing and generation in pgschema.

• Consult gram.y for SQL syntax and DDL structure
• Analyze parser grammar rules and production rules
• Map SQL statements to parse tree nodes and actions

• Grammar rules define statement structure and syntax
• Optional elements (opt_*) allow multiple valid forms
• Lists use recursive rules with comma-separated elements
• Alternatives (|) support multiple valid syntaxes
• Parse nodes and actions build the AST from grammar
• Cross-reference parse_utilcmd.c for transformation logic

1. 1.Identify SQL statement type from grammar rules
2. 2.Locate production rule in gram.y using grep
3. 3.Analyze grammar structure: terminals, non-terminals, actions
4. 4.Trace through related rules and parse actions
5. 5.Apply syntax rules to parse or generate DDL in pgschema