In the T-SQL scripting language, you can use the SQL CASE statement to evaluate a condition and return one or more result expressions. This SQL Tutorial will teach you when and how you can use CASE in T-SQL statements. Solution TheCASE expressionis used to build IF … THEN … ELSE stat...
We can add as manyWHEN ... THENconditions as required in theCASEstatement. For example, -- multiple CASE conditions in SQLSELECTcustomer_id, first_name,CASEWHENcountry ='USA'THEN'United States of America'WHENcountry ='UK'THEN'United Kingdom'ENDAScountry_nameFROMCustomers; Run Code Here, the...
The case statement in SQL returns a value on a specified condition. We can use a Case statement in select queries along with Where, Order By, and Group By clause. It can be used in the Insert statement as well. In this article, we would explore the CASE statement and its various use...
SQL - Having Clause SQL - AND & OR SQL - BOOLEAN (BIT) Operator SQL - LIKE Operator SQL - IN Operator SQL - ANY, ALL Operators SQL - EXISTS Operator SQL - CASE SQL - NOT Operator SQL - NOT EQUAL SQL - IS NULL SQL - IS NOT NULL SQL - NOT NULL SQL - BETWEEN Operator SQL -...
case语句与case表达式是plsql流程控制的重要组成部分,尽管其使用方法较为简单,但容易混淆。...本文将描述case语句与case表达式并给出演示以便于更好理解两者的异同及使用时的注意事项。...WHEN EXPRESSION N THEN STATEMENT N; ELSE STATEMENT N+1; END CASE; --简单的case语句是指SELECTOR中得到的值或结果与EXPR...
然后我们观察到t2.date总是在case语句的两种情况下进行比较,即non-null。我们可以用下面的coalesce语句来表示case-statement: t2.date = coalesce(t1.date, t3date) 它看起来干净多了,但在功能上仍然与case语句相同。 请注意,如果您没有从t2和t3投射任何值,那么进行where date in (select date from t2) or...
SQL---CASE WHEN条件表达式(conditional statement) CASE表达式是用来判断条件的,条件成立时返回某个值,条件不成立时返回另一个值。 语法: CASEWHENComparsionConditionTHENresultWHENComparsionConditionTHENresultELSEotherEND (注:各分支返回的数据类型需一致。)...
null` is not equal to the string `'null'`. 4. Use a `CASE` statement to handle the extracted JSON value: ```sql SELECT CASE JSON_EXTRACT(t1.a, '$.key1') WHEN 'null' THEN NULL WHEN true THEN true ELSE false END FROM t1; ``` Output: ``` +---+ | CASE JSON_EXTRACT(t1.a...
, IN v_str varchar(30) ) BEGIN 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 ...
, IN v_str varchar(30) ) BEGIN 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 ...