IF THEN in SQL SELECT Statement I recently came across the CASE WHEN statement work Similar to IF statement into SQL SELECT , Maybe you’ll find it useful. Create table called Student using SQL Query: CREATE TABLE [dbo].[Student]( [StudentID] [int] NULL, [Marks] [float] NULL ) Inse...
SQL SELECT INTO 语句 SELECT INTO 语句将数据从一个表复制到一个新表中。...SQL SELECT INTO 示例以下 SQL 语句创建 Customers 的备份副本: SELECT * INTO CustomersBackup2017 FROM Customers; 以下...SQL 语句使用 IN 子句将表复制到另一个数据库中的新表中: SELECT * INTO CustomersBackup2017 IN ...
In SQL Server there is anIF…ELSE control flow statement. However, it cannot be used inside a SELECT statement. The closest of IF…THEN operation which can be used in SELECT statements is CASE expression or the IIF function. Let us see how to use CASE and IIF using an example. For thi...
IF Boolean_expression { sql_statement | statement_block } [ ELSE { sql_statement | statement_block } ]Boolean_expression: A boolean expression that returns TRUE or FALSE. If the Boolean expression contains a SELECT statement then it should be enclosed in parentheses. ...
我们可以使用以下流程图了解SQL IF语句。 The condition in SQL IF Statement should return a Boolean value to evaluate SQL IF语句中的条件应返回一个布尔值以求值 We can specify a Select statement as well in a Boolean expression, but it should enclose in parentheses 我们也可以在布尔表达式中指定Select...
parent IF...ELSE. (Note that the logic in this program can be simplified considerably by calculating each employee's yearly compensation using an NVL function within the SELECT statement of the cursor declaration; however, the purpose of this example is to demonstrate how IF statements can be ...
如果XML元素嵌入在<script>XML元素中,则可以在注释值中为动态SQL使用XML元素: @Select("<script>SELECT ...</script>") 但是使用<include>元素会触发SQL Mapper配置解析异常,由以下原因引起: org.apache.ibatis.builder.BuilderException: Unknown element in SQL statement. at org.apache.ibatis.scripting.xmltags....
The following example uses an if statement to check if a query returns any rows: do $$ declare selected_film film%rowtype; input_film_id film.film_id%type = 0; begin select * from film into selected_film where film_id = input_film_id; if not found then raise notice'The film % co...
IFboolean_expression{sql_statement|statement_block} [ELSE{sql_statement|statement_block} ] 参数 boolean_expression 返回TRUE或FALSE. 如果布尔表达式包含语句SELECT,则必须将SELECT语句括在括号中。 { sql_statement | statement_block } 使用语句块定义的任何 Transact-SQL 语句或语句分组。 除非使用了语句块,IF...
如果XML元素嵌入在<script>XML元素中,则可以在注释值中为动态SQL使用XML元素: @Select("<script>SELECT ...</script>") 但是使用<include>元素会触发SQL Mapper配置解析异常,由以下原因引起: org.apache.ibatis.builder.BuilderException: Unknown element in SQL statement. at org.apache.ibatis.scripting.xmltags....