From 488b267335dd17a4cc51cc281ffb8e0d32fbee09 Mon Sep 17 00:00:00 2001 From: Gareth Palmer Date: Wed, 25 Mar 2020 18:57:58 +1300 Subject: [PATCH] Implement INSERT SET syntax Allow the target column and values of an INSERT statement to be specified using a SET clause in the same manner as that of an UPDATE statement. The advantage of using the INSERT SET style is that the columns and values are kept together, which can make changing or removing a column or value from a large list easier. A simple example that uses SET instead of a VALUES() clause: INSERT INTO t SET c1 = 'foo', c2 = 'bar', c3 = 'baz'; Values can also be sourced from other tables similar to the INSERT INTO SELECT FROM syntax: INSERT INTO t SET c1 = x.c1, c2 = x.c2 FROM x WHERE x.c2 > 10 LIMIT 10; INSERT SET is not part of any SQL standard, however this syntax is also implemented by MySQL. Their implementation does not support specifying a FROM clause. --- doc/src/sgml/ref/insert.sgml | 56 +++++++++++++++- src/backend/parser/gram.y | 65 ++++++++++++++++++- src/backend/parser/parse_expr.c | 8 ++- src/test/regress/expected/insert.out | 13 ++-- src/test/regress/expected/insert_conflict.out | 2 + src/test/regress/expected/with.out | 20 ++++++ src/test/regress/sql/insert.sql | 1 + src/test/regress/sql/insert_conflict.sql | 3 + src/test/regress/sql/with.sql | 9 +++ 9 files changed, 169 insertions(+), 8 deletions(-) diff --git a/doc/src/sgml/ref/insert.sgml b/doc/src/sgml/ref/insert.sgml index e829c61642..3542f98d02 100644 --- a/doc/src/sgml/ref/insert.sgml +++ b/doc/src/sgml/ref/insert.sgml @@ -28,6 +28,16 @@ INSERT INTO table_name [ AS conflict_target ] conflict_action ] [ RETURNING * | output_expression [ [ AS ] output_name ] [, ...] ] + +[ WITH [ RECURSIVE ] with_query [, ...] ] +INSERT INTO table_name [ AS alias ] + [ OVERRIDING { SYSTEM | USER} VALUE ] + SET { column_name = { expression | DEFAULT } } [, ...] + [ FROM from_clause ] + [ ON CONFLICT [ conflict_target ] conflict_action ] + [ RETURNING * | output_expression [ [ AS ] output_name ] [, ...] ] + + where conflict_target can be one of: ( { index_column_name | ( index_expression ) } [ COLLATE collation ] [ opclass ] [, ...] ) [ WHERE index_predicate ] @@ -254,6 +264,18 @@ INSERT INTO table_name [ AS + + from_clause + + + A list of table expressions, allowing columns from other tables + to be used as values in the expression. + Refer to the statement for a + description of the syntax. + + + + DEFAULT @@ -631,6 +653,15 @@ INSERT INTO films (code, title, did, date_prod, kind) VALUES + + Insert a row using SET syntax: + + +INSERT INTO films SET code = 'MH832', title = 'Blade Runner', + did = 201, date_prod = DEFAULT, kind = 'SciFi'; + + + This example inserts some rows into table films from a table tmp_films @@ -677,6 +708,16 @@ WITH upd AS ( INSERT INTO employees_log SELECT *, current_timestamp FROM upd; + + Insert multiple rows into employees_log containing +the hours worked by each employee from time_sheets. + +INSERT INTO employees_log SET id = time_sheets.employee, + total_hours = sum(time_sheets.hours) FROM time_sheets + WHERE time_sheets.date ≥ '2019-11-15' GROUP BY time_sheets.employee; + + + Insert or update new distributors as appropriate. Assumes a unique index has been defined that constrains values appearing in the @@ -733,6 +774,18 @@ INSERT INTO distributors (did, dname) VALUES (9, 'Antwerp Design') INSERT INTO distributors (did, dname) VALUES (10, 'Conrad International') ON CONFLICT (did) WHERE is_active DO NOTHING; + + Insert a new film into watched_films or increment the + number of times seen. Returns the new seen count, example assumes a + unique index has been defined that constrains the values appearing in + the title and year columns and + that seen_count defaults to 1. + +INSERT INTO watched_films SET title = 'Akira', year = 1988 + ON CONFLICT (title, year) DO UPDATE SET seen_count = watched_films.seen_count + 1 + RETURNING watched_films.seen_count; + + @@ -743,7 +796,8 @@ INSERT INTO distributors (did, dname) VALUES (10, 'Conrad International') the RETURNING clause is a PostgreSQL extension, as is the ability to use WITH with INSERT, and the ability to - specify an alternative action with ON CONFLICT. + specify an alternative action with ON CONFLICT, and the + ability to specify the inserted columns using SET. Also, the case in which a column name list is omitted, but not all the columns are filled from the VALUES clause or query, diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y index 7e384f956c..31a02389a0 100644 --- a/src/backend/parser/gram.y +++ b/src/backend/parser/gram.y @@ -465,7 +465,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query); %type OptSeqOptList SeqOptList OptParenthesizedSeqOptList %type SeqOptElem -%type insert_rest +%type insert_rest insert_set_clause %type opt_conf_expr %type opt_on_conflict @@ -11029,6 +11029,15 @@ insert_rest: $$->override = $5; $$->selectStmt = $7; } + | insert_set_clause + { + $$ = $1; + } + | OVERRIDING override_kind VALUE_P insert_set_clause + { + $$ = $4; + $$->override = $2; + } | DEFAULT VALUES { $$ = makeNode(InsertStmt); @@ -11060,6 +11069,57 @@ insert_column_item: } ; +insert_set_clause: + SET set_clause_list from_clause where_clause group_clause + having_clause window_clause opt_sort_clause opt_select_limit + opt_for_locking_clause + { + SelectStmt *n = makeNode(SelectStmt); + List *values = NIL; + ListCell *col_cell; + ResTarget *res_col; + + foreach(col_cell, $2) + { + res_col = (ResTarget *) lfirst(col_cell); + + if (IsA(res_col->val, MultiAssignRef)) + ereport(ERROR, + (errcode(ERRCODE_SYNTAX_ERROR), + errmsg("INSERT SET does not support multi-assignment of columns."), + errhint("Specify the column assignments separately."), + parser_errposition(@2))); + } + + if ($3 == NULL) + { + foreach(col_cell, $2) + { + res_col = (ResTarget *) lfirst(col_cell); + values = lappend(values, res_col->val); + } + n->valuesLists = list_make1(values); + } + else + { + n->targetList = $2; + n->fromClause = $3; + } + + n->whereClause = $4; + n->groupClause = $5; + n->havingClause = $6; + n->windowClause = $7; + insertSelectOptions(n, $8, $10, + list_nth($9, 0), list_nth($9, 1), + NULL, + yyscanner); + $$ = makeNode(InsertStmt); + $$->cols = $2; + $$->selectStmt = (Node *) n; + } + ; + opt_on_conflict: ON CONFLICT opt_conf_expr DO UPDATE SET set_clause_list where_clause { @@ -11443,6 +11503,9 @@ select_clause: * * NOTE: only the leftmost component SelectStmt should have INTO. * However, this is not checked by the grammar; parse analysis must check it. + * + * NOTE: insert_set_clause also has SELECT-like syntax so if you add any + * clauses after from_clause here you may need to add them there as well. */ simple_select: SELECT opt_all_clause opt_target_list diff --git a/src/backend/parser/parse_expr.c b/src/backend/parser/parse_expr.c index 831db4af95..644f1919fd 100644 --- a/src/backend/parser/parse_expr.c +++ b/src/backend/parser/parse_expr.c @@ -1572,8 +1572,12 @@ transformMultiAssignRef(ParseState *pstate, MultiAssignRef *maref) Query *qtree; TargetEntry *tle; - /* We should only see this in first-stage processing of UPDATE tlists */ - Assert(pstate->p_expr_kind == EXPR_KIND_UPDATE_SOURCE); + /* + * We should only see this in first-stage processing of UPDATE tlists + * (UPDATE_SOURCE), an INSERT SET tlist (VALUES_SINGLE). + */ + Assert(pstate->p_expr_kind == EXPR_KIND_UPDATE_SOURCE || + pstate->p_expr_kind == EXPR_KIND_VALUES_SINGLE); /* We only need to transform the source if this is the first column */ if (maref->colno == 1) diff --git a/src/test/regress/expected/insert.out b/src/test/regress/expected/insert.out index 45d77ba3a5..057147d76d 100644 --- a/src/test/regress/expected/insert.out +++ b/src/test/regress/expected/insert.out @@ -9,6 +9,7 @@ insert into inserttest (col2, col3) values (3, DEFAULT); insert into inserttest (col1, col2, col3) values (DEFAULT, 5, DEFAULT); insert into inserttest values (DEFAULT, 5, 'test'); insert into inserttest values (DEFAULT, 7); +insert into inserttest set col1 = DEFAULT, col2 = 9; select * from inserttest; col1 | col2 | col3 ------+------+--------- @@ -16,7 +17,8 @@ select * from inserttest; | 5 | testing | 5 | test | 7 | testing -(4 rows) + | 9 | testing +(5 rows) -- -- insert with similar expression / target_list values (all fail) @@ -44,7 +46,8 @@ select * from inserttest; | 5 | testing | 5 | test | 7 | testing -(4 rows) + | 9 | testing +(5 rows) -- -- VALUES test @@ -58,10 +61,11 @@ select * from inserttest; | 5 | testing | 5 | test | 7 | testing + | 9 | testing 10 | 20 | 40 -1 | 2 | testing 2 | 3 | values are fun! -(7 rows) +(8 rows) -- -- TOASTed value test @@ -74,11 +78,12 @@ select col1, col2, char_length(col3) from inserttest; | 5 | 7 | 5 | 4 | 7 | 7 + | 9 | 7 10 | 20 | 2 -1 | 2 | 7 2 | 3 | 15 30 | 50 | 10000 -(8 rows) +(9 rows) drop table inserttest; -- diff --git a/src/test/regress/expected/insert_conflict.out b/src/test/regress/expected/insert_conflict.out index 1338b2b23e..4d6538b1fb 100644 --- a/src/test/regress/expected/insert_conflict.out +++ b/src/test/regress/expected/insert_conflict.out @@ -236,6 +236,8 @@ insert into insertconflicttest values (2, 'Orange') on conflict (key, key, key) insert into insertconflicttest values (1, 'Apple'), (2, 'Orange') on conflict (key) do update set (fruit, key) = (excluded.fruit, excluded.key); +-- Using insert set syntax +insert into insertconflicttest set key = 1, fruit = 'Banana' on conflict (key) do update set fruit = excluded.fruit; -- Give good diagnostic message when EXCLUDED.* spuriously referenced from -- RETURNING: insert into insertconflicttest values (1, 'Apple') on conflict (key) do update set fruit = excluded.fruit RETURNING excluded.fruit; diff --git a/src/test/regress/expected/with.out b/src/test/regress/expected/with.out index 67eaeb4f3e..7ec234b186 100644 --- a/src/test/regress/expected/with.out +++ b/src/test/regress/expected/with.out @@ -952,6 +952,26 @@ SELECT * FROM y; 10 (10 rows) +TRUNCATE TABLE y; +WITH t AS ( + SELECT generate_series(1, 10) AS a +) +INSERT INTO y SET a = t.a+20 FROM t; +SELECT * FROM y; + a +---- + 21 + 22 + 23 + 24 + 25 + 26 + 27 + 28 + 29 + 30 +(10 rows) + DROP TABLE y; -- -- error cases diff --git a/src/test/regress/sql/insert.sql b/src/test/regress/sql/insert.sql index 23885f638c..0306669167 100644 --- a/src/test/regress/sql/insert.sql +++ b/src/test/regress/sql/insert.sql @@ -7,6 +7,7 @@ insert into inserttest (col2, col3) values (3, DEFAULT); insert into inserttest (col1, col2, col3) values (DEFAULT, 5, DEFAULT); insert into inserttest values (DEFAULT, 5, 'test'); insert into inserttest values (DEFAULT, 7); +insert into inserttest set col1 = DEFAULT, col2 = 9; select * from inserttest; diff --git a/src/test/regress/sql/insert_conflict.sql b/src/test/regress/sql/insert_conflict.sql index 43691cd335..e0eb2df0c8 100644 --- a/src/test/regress/sql/insert_conflict.sql +++ b/src/test/regress/sql/insert_conflict.sql @@ -97,6 +97,9 @@ insert into insertconflicttest values (1, 'Apple'), (2, 'Orange') on conflict (key) do update set (fruit, key) = (excluded.fruit, excluded.key); +-- Using insert set syntax +insert into insertconflicttest set key = 1, fruit = 'Banana' on conflict (key) do update set fruit = excluded.fruit; + -- Give good diagnostic message when EXCLUDED.* spuriously referenced from -- RETURNING: insert into insertconflicttest values (1, 'Apple') on conflict (key) do update set fruit = excluded.fruit RETURNING excluded.fruit; diff --git a/src/test/regress/sql/with.sql b/src/test/regress/sql/with.sql index f85645efde..d3e04bbad9 100644 --- a/src/test/regress/sql/with.sql +++ b/src/test/regress/sql/with.sql @@ -404,6 +404,15 @@ DELETE FROM y USING t WHERE t.a = y.a RETURNING y.a; SELECT * FROM y; +TRUNCATE TABLE y; + +WITH t AS ( + SELECT generate_series(1, 10) AS a +) +INSERT INTO y SET a = t.a+20 FROM t; + +SELECT * FROM y; + DROP TABLE y; -- -- 2.17.1