示例1:布尔表达式中带有数字值的IF语句(Example 1: IF Statement with a numeric value in a Boolean expression) In the following example, we specified a numeric value in the Boolean expression that is always TRUE. It prints the statement for If statement because the condition is true. 在下面的示...
IF boolean-expression THEN statements END IF; You can nest IF statements so that alternative IF statements are invoked, depending on whether the conditions of an outer IF statement evaluate to TRUE or FALSE. In the following example, the outer IF...THEN...ELSE statement tests whether or not ...
9、说明:创建视图:create view viewname as select statement 删除视图:drop view viewname10、说明:几个简单的基本的sql语句选择:select...RecID 是自增长字段, 写一个SQL语句, 找出表的第31到第40个记录。 ...Transact-SQL 语句影响的行数的信息。...SET NOCOUNT 为 ON 时,不返回计数(表示受 Transact-SQ...
PL/pgSQL provides you with three forms of the if statements: if then if then else if then elsif 1) PL/pgSQL if-then statement The following illustrates the simplest form of the if statement: if condition then statements; end if; The if statement executes statements when a condition is ...
T-SQL WITH 分号问题 使用with 前面有sql语句时候 运行 with tempTbale(id) as ( select ... ) select * from tempTbale 运行上面语句 提示下面错误 Incorrect syntax near the keyword 'with'. If this statement is a common table expression, an xmlnamespaces clause or a change tracking context clause...
用if判断,但有以下条件 TheIFstatementis part of the default procedural language PL/pgSQL. You need to create a function or execute an ad-hoc statement with theDOcommand.、 exist使用要求和if一样 1 2 3 4 5 6 7 8 9 10 11 DO $do$ ...
在PL/SQL 環境定義內使用 IF 陳述式,以根據特定準則來執行 SQL 陳述式。 IF 陳述式有四種形式: 如果...then...End If 如果...then...ELSE ...End If 如果...then...ELSE IF ...End If 如果...then...ELSIF ...then...ELSE ...End If 如果...then...End If 此陳述式的語法如下: IF ...
Here, the SQL command changes the value of thefirst_namecolumn toJohnnyifcustomer_idis equal to1. Example: SQL UPDATE Statement Update Multiple Values in a Row We can also update multiple values in a single row at once. For example, ...
Querying with SQL Statements IntroductionThe SQL Query command allows you to select the data that meets the specific criteria from existing data through a written statement or logical expression. The data types are: point, line, region, text, CAD, attribute table, 3D point, 3D line, 3D region...
In SQL, the ALTER TABLE command is used to modify the structure of an existing table. In this tutorial, you will learn about the SQL ALTER TABLE statement with the help of examples.