sql case statement
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...
2.举例: SELECTOrderID, Quantity,CASEWHENQuantity>30THEN'The quantity is greater than 30'WHENQuantity=30THEN'The quantity is 30'ELSE'The quantity is under 30'ENDASQuantityTextFROMOrderDetails; SELECTCustomerName, City, CountryFROMCustomersORDERBY(CASEWHENCityISNULLTHENCountryELSECityEND); 以上例子等...
The SQLCASEstatement evaluates a list of conditions and adds a column with values based on the condition. For example, -- add a new column 'order_volume' in the Orders table-- and flag any order greater than 10000 as 'Large Order'-- and smaller than 10000 as 'Small Order'SELECT*,CASE...
The following SQL script does the same, but rather uses the IF … ELSE construct to switch between two different statements, instead of calculating the result in one single statement: SETDATEFIRST1-- first day of the week is a MondayIF(DATEPART(WEEKDAY,GETDATE())=1)BEGINSELECT'Monday'ENDEL...
Learn how to use the SQL CASE statement to perform conditional logic in your SQL queries effectively.
在SQL Server中,SELECT语句用于从数据库中检索数据。CASE语句是SELECT语句中的一种条件表达式,用于根据条件返回不同的结果。 CASE语句有两种形式:简单CASE表达式和搜索CA...
Simple Case Statement CASE [input_expression] WHEN when_expression THEN when_true_result_expression [...n] [ELSE else_result_expression] END Search Case Statement CASE WHEN Boolean_expression THEN when_true_result_expression [...n] [ELSE else_result_expression] END ...
This SQL Server tutorial explains how to use the SQL Server (Transact-SQL) CASE statement with syntax and examples. In SQL Server (Transact-SQL), the CASE statement has the functionality of an IF-THEN-ELSE statement. You can use the CASE statement within
CASE selector WHEN selector_value_1 THEN statements_1 WHEN selector_value_1 THEN statement_2 ... ELSE else_statements END CASE; Code language: PostgreSQL SQL dialect and PL/pgSQL (pgsql) Let’s examine the syntax of the simple CASE statement in detail: 1) selector The selector is an...