SQL中的CASE WHEN使用 Case具有两种格式。简单Case函数和Case搜索函数。...简单Case函数的写法相对比较简洁,但是和Case搜索函数相比,功能方面会有些限制,比如写判断式。 还有一个需要注意的问题,Case函数只返回第一个符合条件的值,剩下的Case部分将会被自动忽略。...语句完成不同条件的分组。...但是那
CASE 陳述式的 WHEN 子句定義當滿足時決定控制流程的值。 以下是具有含簡式 case-statement-when-clause 之 CASE 陳述式的 SQL 程序範例: CREATE PROCEDURE UPDATE_DEPT (IN p_workdept) LANGUAGE SQL BEGIN DECLARE v_workdept CHAR(3); SET v_workdept = p_workdept; CASE v_workdept WHEN 'A00' THEN...
CASE WHEN in SQL operates very similarly to “if then” statements in other programming languages. Replace the “if” with CASE WHEN and “else if” with WHEN, and the rest matches: Note: CASE WHEN statements will always output new values to a new column which is different than “if then...
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...
If the first condition is met (evaluates to TRUE), the statements following the THEN keyword are run in sequence until a WHEN, ELSE, or END CASE is reached. Otherwise, if there is any WHEN statement for which the condition is met, the statements following the THEN keyword are run until ...
Both formats support anoptional ELSEargument. CASE can be used in any statement or clause that allows a valid expression. For example, you can use CASE in statements such as SELECT, UPDATE, DELETE and SET, and in clauses such as select_list, IN, WHERE, ORDER BY, and HAVING. ...
An example of this would be the simplified cut down version below where I am adding points to aRatings columnthat will be displayed in the final results. I used multipleCASE WHEN THEN ELSE END,statements to check various stats a horse may have and if they meet the criteria I append a sc...
Different Formats of CASE Statements A simple CASE statement expression In this format, we evaluate one expression against multiple values. In a simple case statement, it evaluates conditions one by one. Once the condition and expression are matched, it returns the expression mentioned in THEN cla...
CASE can be used in any statement or clause that allows a valid expression. For example, you can use CASE in statements such as SELECT, UPDATE, DELETE and SET, and in clauses such as select_list, IN, WHERE, ORDER BY, and HAVING. ...
CASE WHEN condition_1 THEN statements_1 WHEN condition_2 THEN statements_2 ... WHEN condition_n THEN statements_n [ ELSE else_statements ] END CASE;] Code language: PostgreSQL SQL dialect and PL/pgSQL (pgsql) The searched CASE statement follows the rules below: The conditions in the WHEN...