SQL 方言参考/编写查询/替换查询
< SQL 方言参考
替换查询在没有具有此主键的行时插入新行，或者如果存在则更新现有行。SQL:2003 标准引入了 MERGE 语句来实现此功能，而其他实现提供了名为“REPLACE”的类似查询或所谓的“Upsert”查询（UPDATE 和 INSERT 的混合词）。
| 标准 | MERGE 语句可用于执行替换查询MERGE INTO table_name1 USING table_name2 ON (condition)
WHEN MATCHED THEN UPDATE SET column1 = value1 [, column2 = value2 ...]
WHEN NOT MATCHED THEN INSERT columns VALUES (values)
请注意，MERGE 的功能远不止执行替换查询。 |
|---|---|
| DB2 | MERGE 语句MERGE INTO phonebook AS p
USING ( VALUES ('john doe', '1234' ) ) AS v(name, extension)
ON ( p.name = v.name )
WHEN MATCHED
UPDATE SET p.extension = v.extension
WHEN NOT MATCHED
INSERT VALUES ( v.name, v.extension )
|
| Firebird | MERGE 语句MERGE INTO phonebook B
USING (
SELECT name
FROM phonebook
WHERE name = 'john doe') E
ON (B.name = E.name)
WHEN MATCHED THEN
UPDATE SET B.extension = '1234'
WHEN NOT MATCHED THEN
INSERT (name, extension)
VALUES ('john doe', '1234);
非标准简化形式 UPDATE OR INSERT INTO phonebook (name, extension)
VALUES ('john doe', '1234')
MATCHING (name)
|
| Ingres | ? |
| Linter | ? |
| MonetDB | ? |
| MSSQL | MERGE 语句（从版本SQL Server 2008开始）DECLARE @UnitMeasureCode nchar(3) = 'ABC'
DECLARE @Name varchar(25) = 'Test name'
MERGE INTO Production.UnitMeasure AS target
USING (SELECT @UnitMeasureCode, @Name) AS source (UnitMeasureCode, Name)
ON (target.UnitMeasureCode = source.UnitMeasureCode)
WHEN MATCHED THEN
UPDATE SET Name = source.Name
WHEN NOT MATCHED THEN
INSERT (UnitMeasureCode, Name)
VALUES (source.UnitMeasureCode, source.Name)
|
| MySQL | 允许 3 种语法：非标准 REPLACE 查询、（从 4.1 开始）INSERT ... ON DUPLICATE KEY UPDATE 以及 IF EXISTS 的变体。REPLACE [INTO] table [(columns)] VALUES (values) INSERT INTO table (columns) VALUES (values) ON DUPLICATE KEY UPDATE column1=value1, column2=value2 IF EXISTS( SELECT * FROM phonebook WHERE name = 'john doe' )
THEN UPDATE phonebook SET extension = '1234' WHERE name = 'john doe'
ELSE INSERT INTO phonebook VALUES( 'john doe','1234' )
END IF
|
| Oracle | MERGE 语句MERGE INTO phonebook B
USING (
SELECT name_id
FROM phonebook
WHERE name = 'john doe') E
ON (B.name = E.name)
WHEN MATCHED THEN
UPDATE SET B.extension = '1234'
WHEN NOT MATCHED THEN
INSERT (B.name, B.extension)
VALUES ('john doe', '1234);
IF EXISTS( SELECT * FROM phonebook WHERE name = 'john doe' )
UPDATE phonebook SET extension = '1234' WHERE name = 'john doe'
ELSE
INSERT INTO phonebook VALUES( 'john doe','1234' )
|
| PostgreSQL | 从版本 9.5 开始，INSERT INTO...ON CONFLICT... 语法受 MySQL 启发INSERT INTO distributors (did, dname)
VALUES (5, 'Gizmo Transglobal'), (6, 'Associated Computing, Inc')
ON CONFLICT (did) DO UPDATE SET dname = EXCLUDED.dname;
|
| SQLite | REPLACE 语句REPLACE [INTO] table [(columns)] VALUES (values) （始终删除旧行） |
| Virtuoso | ? |