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expressions in CREATE TABLE. There is no longer an emasculated expression syntax for these things; it's full a_expr for constraints, and b_expr for defaults (unfortunately the fact that NOT NULL is a part of the column constraint syntax causes a shift/reduce conflict if you try a_expr. Oh well --- at least parenthesized boolean expressions work now). Also, stored expression for a column default is not pre-coerced to the column type; we rely on transformInsertStatement to do that when the default is actually used. This means "f1 datetime default 'now'" behaves the way people usually expect it to. BTW, all the support code is now there to implement ALTER TABLE ADD CONSTRAINT and ALTER TABLE ADD COLUMN with a default value. I didn't actually teach ALTER TABLE to call it, but it wouldn't be much work.
This directory does more than tokenize and parse SQL queries. It also creates Query structures for the various complex queries that is passed to the optimizer and then executor. parser.c things start here scan.l break query into tokens scansup.c handle escapes in input keywords.c turn keywords into specific tokens gram.y parse the tokens and fill query-type-specific structures analyze.c handle post-parse processing for each query type parse_clause.c handle clauses like WHERE, ORDER BY, GROUP BY, ... parse_coerce.c used for coercing expressions of different types parse_expr.c handle expressions like col, col + 3, x = 3 or x = 4 parse_oper.c handle operations in expressions parse_agg.c handle aggregates, like SUM(col1), AVG(col2), ... parse_func.c handle functions, table.column and column identifiers parse_node.c create nodes for various structures parse_target.c handle the result list of the query parse_relation.c support routines for tables and column handling parse_type.c support routines for type handling