feat(plisql): accept the Oracle EXECUTE IMMEDIATE spelling for dynamic SQL

src/pl/plisql/src/Makefile

@@ -64,7 +64,7 @@ REGRESS = plisql_array plisql_call plisql_control plisql_copy plisql_domain \
 	plisql_trap plisql_trigger plisql_varprops plisql_nested_subproc \
 	plisql_nested_subproc2 plisql_out_parameter plisql_type_rowtype \
 	plisql_exception plisql_for_loop_implicit plisql_autonomous plisql_bugs plisql_rownum \
-	plisql_package_type_record
+	plisql_package_type_record plisql_execute_immediate
 
 # where to find ora_gen_keywordlist.pl and subsidiary files
 TOOLSDIR = $(top_srcdir)/src/tools

src/pl/plisql/src/expected/plisql_execute_immediate.out

@@ -0,0 +1,92 @@
+--
+-- Tests for the Oracle-compatible EXECUTE IMMEDIATE statement
+--
+CREATE TABLE ei_test (id int, label text);
+-- DDL through EXECUTE IMMEDIATE
+do $$ begin
+    execute immediate 'CREATE TABLE ei_ddl (id int)';
+end $$;
+select count(*) as ei_ddl_rows from ei_ddl;
+ ei_ddl_rows 
+-------------
+           0
+(1 row)
+
+-- DML with Oracle-style :n bind parameters
+do $$ begin
+    execute immediate 'INSERT INTO ei_test VALUES (:1, :2)' using 1, 'one';
+    execute immediate 'INSERT INTO ei_test VALUES (:1, :2)' using 2, 'two';
+end $$;
+select id, label from ei_test order by id;
+ id | label 
+----+-------
+  1 | one
+  2 | two
+(2 rows)
+
+-- single-row query into a variable
+do $$ declare
+    n int;
+begin
+    execute immediate 'SELECT count(*) FROM ei_test' into n;
+    raise notice 'count = %', n;
+end $$;
+NOTICE:  count = 2
+-- INTO before USING (clauses in either order)
+do $$ declare
+    lbl text;
+begin
+    execute immediate 'SELECT label FROM ei_test WHERE id = :1'
+        into lbl using 2;
+    raise notice 'label = %', lbl;
+end $$;
+NOTICE:  label = two
+-- record target
+do $$ declare
+    r ei_test%ROWTYPE;
+begin
+    execute immediate 'SELECT * FROM ei_test WHERE id = :1' into r using 1;
+    raise notice 'row = %, %', r.id, r.label;
+end $$;
+NOTICE:  row = 1, one
+-- dynamic anonymous PL/iSQL block with a bind argument
+do $$ begin
+    execute immediate 'BEGIN INSERT INTO ei_test VALUES (:1, :2); END;'
+        using 3, 'three';
+end $$;
+select count(*) as total from ei_test;
+ total 
+-------
+     3
+(1 row)
+
+-- dynamic string built at runtime
+do $$ declare
+    v_sql text;
+begin
+    v_sql := 'UPDATE ei_test SET label = label || ''!'' WHERE id = ' || 2::text;
+    execute immediate v_sql;
+end $$;
+select label from ei_test where id = 2;
+ label 
+-------
+ two!
+(1 row)
+
+-- NULL dynamic string
+do $$ begin
+    execute immediate null;
+end $$;
+ERROR:  query string argument of EXECUTE is null
+CONTEXT:  PL/iSQL function inline_code_block line 2 at EXECUTE
+-- plain EXECUTE keeps working and shares the same clauses
+do $$ declare
+    v int;
+begin
+    execute 'DELETE FROM ei_test WHERE id = 3';
+    execute 'SELECT count(*) FROM ei_test' into v;
+    raise notice 'after delete = %', v;
+end $$;
+NOTICE:  after delete = 2
+DROP TABLE ei_test;
+DROP TABLE ei_ddl;

src/pl/plisql/src/pl_gram.y

@@ -363,6 +363,7 @@ static	PLiSQL_expr		*build_call_expr(int firsttoken, int location, YYSTYPE *yylv
 %token <keyword>	K_GET
 %token <keyword>	K_HINT
 %token <keyword>	K_IF
+%token <keyword>	K_IMMEDIATE
 %token <keyword>	K_IMPORT
 %token <keyword>	K_IN
 %token <keyword>	K_INFO
@@ -2935,6 +2936,21 @@ stmt_dynexecute : K_EXECUTE
 						PLiSQL_stmt_dynexecute *new;
 						PLiSQL_expr *expr;
 						int endtoken;
+						int tok;
+
+						/*
+						 * Oracle spells the dynamic-SQL statement
+						 * "EXECUTE IMMEDIATE"; accept and skip IMMEDIATE if
+						 * present, pushing back anything else for the
+						 * expression reader.  A variable named "immediate"
+						 * resolves to the keyword in this position (the
+						 * scanner prefers keywords right after a
+						 * statement-introducing keyword), consistent with
+						 * other unreserved keywords.
+						 */
+						tok = yylex(&yylval, &yylloc, yyscanner);
+						if (tok != K_IMMEDIATE)
+							plisql_push_back_token(tok, &yylval, &yylloc, yyscanner);
 
 						expr = read_sql_construct(K_INTO, K_USING, ';',
 												  "INTO or USING or ;",
@@ -3474,6 +3490,7 @@ unreserved_keyword	:
 				| K_FORWARD
 				| K_GET
 				| K_HINT
+				| K_IMMEDIATE
 				| K_IMPORT
 				| K_INFO
 				| K_INSERT

src/pl/plisql/src/pl_unreserved_kwlist.h

@@ -75,6 +75,7 @@ PG_KEYWORD("first", K_FIRST)
 PG_KEYWORD("forward", K_FORWARD)
 PG_KEYWORD("get", K_GET)
 PG_KEYWORD("hint", K_HINT)
+PG_KEYWORD("immediate", K_IMMEDIATE)
 PG_KEYWORD("import", K_IMPORT)
 PG_KEYWORD("info", K_INFO)
 PG_KEYWORD("insert", K_INSERT)

src/pl/plisql/src/sql/plisql_execute_immediate.sql

@@ -0,0 +1,80 @@
+--
+-- Tests for the Oracle-compatible EXECUTE IMMEDIATE statement
+--
+
+CREATE TABLE ei_test (id int, label text);
+
+-- DDL through EXECUTE IMMEDIATE
+do $$ begin
+    execute immediate 'CREATE TABLE ei_ddl (id int)';
+end $$;
+
+select count(*) as ei_ddl_rows from ei_ddl;
+
+-- DML with Oracle-style :n bind parameters
+do $$ begin
+    execute immediate 'INSERT INTO ei_test VALUES (:1, :2)' using 1, 'one';
+    execute immediate 'INSERT INTO ei_test VALUES (:1, :2)' using 2, 'two';
+end $$;
+
+select id, label from ei_test order by id;
+
+-- single-row query into a variable
+do $$ declare
+    n int;
+begin
+    execute immediate 'SELECT count(*) FROM ei_test' into n;
+    raise notice 'count = %', n;
+end $$;
+
+-- INTO before USING (clauses in either order)
+do $$ declare
+    lbl text;
+begin
+    execute immediate 'SELECT label FROM ei_test WHERE id = :1'
+        into lbl using 2;
+    raise notice 'label = %', lbl;
+end $$;
+
+-- record target
+do $$ declare
+    r ei_test%ROWTYPE;
+begin
+    execute immediate 'SELECT * FROM ei_test WHERE id = :1' into r using 1;
+    raise notice 'row = %, %', r.id, r.label;
+end $$;
+
+-- dynamic anonymous PL/iSQL block with a bind argument
+do $$ begin
+    execute immediate 'BEGIN INSERT INTO ei_test VALUES (:1, :2); END;'
+        using 3, 'three';
+end $$;
+
+select count(*) as total from ei_test;
+
+-- dynamic string built at runtime
+do $$ declare
+    v_sql text;
+begin
+    v_sql := 'UPDATE ei_test SET label = label || ''!'' WHERE id = ' || 2::text;
+    execute immediate v_sql;
+end $$;
+
+select label from ei_test where id = 2;
+
+-- NULL dynamic string
+do $$ begin
+    execute immediate null;
+end $$;
+
+-- plain EXECUTE keeps working and shares the same clauses
+do $$ declare
+    v int;
+begin
+    execute 'DELETE FROM ei_test WHERE id = 3';
+    execute 'SELECT count(*) FROM ei_test' into v;
+    raise notice 'after delete = %', v;
+end $$;
+
+DROP TABLE ei_test;
+DROP TABLE ei_ddl;