Approach: UsingUPDATEandCASE...WHEN[Accepted] Algorithm To dynamically set a value to a column, we can useUPDATEstatement together whenCASE...WHEN...flow control statement. MySQL UPDATEsalarySETsex=CASEsexWHEN'm'THEN'f'ELSE'm'END;
收到的错误是SQL UPDATE 语句 Update 语句用于修改表中的数据。 语法： UPDATE 表名称 SET 列名称 ...
CASE n_str WHEN n_str = 'profileStatus' THEN UPDATE tbl_contact SET status = 'A' WHERE id = id; -- The above statement updates the entire table instead of the right row WHEN n_str = 'phoneNumberMobile' THEN UPDATE tbl_contact SET mobile_phone = v_str ...
Unlike thecasewhenusing PARTITIONwithanINSERTorREPLACEstatement, an otherwise validUPDATE... PARTITION statementisconsidered successful evenifno rowsinthe listed partitions (orsubpartitions) match the where_condition.Formore informationandexamples, see ...
END ends the CASE statement AS specifies the name alias_name for the new column table is the name of the table. Note: The syntax of CASE always starts with the CASE keyword and ends with the END keyword followed by a column name alias. Example: Voter Eligibility Using SQL CASE -- add...
-- update all rowsUPDATECustomersSETcountry ='NP'; Run Code Here, the SQL command changes the value of thecountrycolumn toNPfor all rows. Note:We should be cautious while using theUPDATEstatement. If we omit theWHEREclause, all the rows will be changed, and this change is irreversible. ...
USE tempdb; GO -- UPDATE statement with CTE references that are correctly matched. DECLARE @x TABLE (ID INT, Value INT); DECLARE @y TABLE (ID INT, Value INT); INSERT @x VALUES (1, 10), (2, 20); INSERT @y VALUES (1, 100),(2, 200); WITH cte AS (SELECT * FROM @x) UPD...
CASEcan be used in any statement or clause that allows a valid expression. For example, you can useCASEin statements such as SELECT, UPDATE, DELETE and SET, and in clauses such as, IN, WHERE, ORDER BY, and HAVING. Transact-SQL syntax...
USE tempdb; GO -- UPDATE statement with CTE references that are correctly matched. DECLARE @x TABLE (ID INT, Value INT); DECLARE @y TABLE (ID INT, Value INT); INSERT @x VALUES (1, 10), (2, 20); INSERT @y VALUES (1, 100),(2, 200); WITH cte AS (SELECT * FROM @x) UPD...
CASE n_str WHEN n_str = 'profileStatus' THEN UPDATE tbl_contact SET status = 'A' WHERE id = id; -- The above statement updates the entire table instead of the right row WHEN n_str = 'phoneNumberMobile' THEN UPDATE tbl_contact SET mobile_phone = v_str ...