Support TSQL PIVOT operator (babelfish-for-postgresql#165)

Add support for PIVOT in babelfish Task: BABEL-284 Signed-off-by: Yanjie Xu <[email protected]>
amazon-aurora · Nov 22, 2023 · d807167 · d807167
1 parent a0bb316
commit d807167
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Showing 3 changed files with 20 additions and 2 deletions.
diff --git a/src/backend/parser/analyze.c b/src/backend/parser/analyze.c
@@ -88,6 +88,9 @@ pre_transform_setop_tree_hook_type pre_transform_setop_tree_hook = NULL;
 /* Hook to reset a query's targetlist after modification in pre_transfrom_sort_clause */
 pre_transform_setop_sort_clause_hook_type pre_transform_setop_sort_clause_hook = NULL;
 
+/* Hooks for transform TSQL pivot clause in select stmt */
+transform_pivot_clause_hook_type transform_pivot_clause_hook = NULL;
+
 static Query *transformOptionalSelectInto(ParseState *pstate, Node *parseTree);
 static Query *transformDeleteStmt(ParseState *pstate, DeleteStmt *stmt);
 static Query *transformInsertStmt(ParseState *pstate, InsertStmt *stmt);
@@ -120,7 +123,6 @@ static void transformLockingClause(ParseState *pstate, Query *qry,
 static bool test_raw_expression_coverage(Node *node, void *context);
 #endif
 
-
 /*
  * parse_analyze_fixedparams
  *		Analyze a raw parse tree and transform it to Query form.
@@ -1365,7 +1367,6 @@ count_rowexpr_columns(ParseState *pstate, Node *expr)
 	return -1;
 }
 
-
 /*
  * transformSelectStmt -
  *	  transforms a Select Statement
@@ -1404,6 +1405,11 @@ transformSelectStmt(ParseState *pstate, SelectStmt *stmt)
 	/* make WINDOW info available for window functions, too */
 	pstate->p_windowdefs = stmt->windowClause;
 
+	if (stmt->isPivot && transform_pivot_clause_hook)
+	{
+		(*transform_pivot_clause_hook)(pstate, stmt);
+	}
+
 	/* process the FROM clause */
 	transformFromClause(pstate, stmt->fromClause);
 

diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
@@ -2047,6 +2047,14 @@ typedef struct SelectStmt
 	struct SelectStmt *larg;	/* left child */
 	struct SelectStmt *rarg;	/* right child */
 	/* Eventually add fields for CORRESPONDING spec here */
+
+	/* These fields are used only in SelectStmt with PIVOT keyword */
+	bool	isPivot;
+	struct SelectStmt *srcSql;
+	struct SelectStmt *catSql;
+	List	*value_col_strlist;
+	char	*pivotCol;
+	Node	*aggFunc;
 } SelectStmt;
 
 

diff --git a/src/include/parser/analyze.h b/src/include/parser/analyze.h
@@ -64,6 +64,10 @@ extern PGDLLIMPORT pre_transform_setop_tree_hook_type pre_transform_setop_tree_h
 typedef void (*pre_transform_setop_sort_clause_hook_type) (ParseState *pstate, Query *qry, List *sortClause, Query *leftmostQuery);
 extern PGDLLIMPORT pre_transform_setop_sort_clause_hook_type pre_transform_setop_sort_clause_hook;
 
+/* Hook for transform pivot clause in tsql select stmt */
+typedef void (*transform_pivot_clause_hook_type)(ParseState *pstate, SelectStmt *stmt);
+extern PGDLLIMPORT transform_pivot_clause_hook_type transform_pivot_clause_hook;
+
 extern Query *parse_analyze_fixedparams(RawStmt *parseTree, const char *sourceText,
 										const Oid *paramTypes, int numParams, QueryEnvironment *queryEnv);
 extern Query *parse_analyze(RawStmt *parseTree, const char *sourceText,