BOOLEAN表达式是PL/SQL语言中很常用的一种表达式类型,它用于比较两个条件,来确定其是否为真或假。 在PL/SQL中,BOOLEAN表达式可以用于条件判断或在循环语句中作为终止条件。其语法非常简单,只需要使用逻辑运算符对两个条件进行比较。PL/SQL支持的逻辑运算符有AND、OR和NOT三种,这些运算符可以将结果组合成更复杂的布尔...
SQL>setserverout onSQL>DECLARE2gradeCHAR(1):='B';3appraisalVARCHAR2(20);4BEGIN5appraisal:=6CASEgrade7WHEN'A'THEN'Excellent'8WHEN'B'THEN'Very Good'9WHEN'C'THEN'Good'10WHEN'D'THEN'Fair'11WHEN'F'THEN'Poor'12ELSE'No such grade'13END;14DBMS_OUTPUT.PUT_LINE('Grade '||grade||' is '...
PL/SQL块以BEGIN开始或以局部变量声明开始,以END或END function_name结束。在PL/SQL块中,可以使用多个RETURN语句,但是必须保证至少有一条RETURN语句存在。函数每一次运行只有一个RETURN语句被执行。 举例:。。。CREATE OR REPLACE FUNCTION get_sal(p_id IN emp.empno%TYPE)RETURN NUMBERISv_salary emp.sal%TYPE :...
SQL>BEGIN SQL>SELECT * FROM dept; 删除过程 DROP PROCEDURE raise_salary; 创建函数 CREATE [OR REPLACE] FUNCTION function_name [(argument1 [IN | OUT | IN OUT] data_type , argument2 [IN | OUT | IN OUT] data_type,…)] RETURN data_type IS |AS BEGIN [EXCEPTION RETURN expression;] ...
member function get_info return varchar2 is begin return '雇员名:'||name||',家庭住址:'||address; end; end; PL/SQL块中只能直接嵌入SELECT,DML(INSERT,UPDATE,DELETE)以及事务控制语句(COMMIT,ROLLBACK,SAVEPOINT),而不能直接嵌入DDL语句(CREATE,ALTER,DROP)和DCL语句(GRANT,REVOKE) ...
Oracle - FUNCTION getFunction ( dbId IN NUMBER) RETURN NUMBER IS <Function Body> MySQL - CREATE FUNCTION getFunction ( dbId IN INT) RETURNS INT RETURN <Function Body> 10) Replace functions as follows Oracle => MySQL --- NVL() => IFNULL() Find RegEx - NVL\((...
PL/SQL recognizes the following SQL pseudocolumns, which return specific data items:CURRVAL,LEVEL,NEXTVAL,ROWID, andROWNUM. Pseudocolumns are not actual columns in a table but they behave like columns. For example, you can select values from a pseudocolumn. However, you cannot insert into, upda...
Example 13-2 illustrates this. Function json_transform can accept as input, and return as output, any SQL data type that supports JSON data: JSON, VARCHAR2, CLOB, or BLOB. (Data type JSON is available only if database initialization parameter compatible is 20 or greater.) The default ...
bool (System.Boolean) ConnectionLifetime OracleConnectionPool ODP.NET 属性。 指定连接的最大持续时间(以秒为单位)。 默认值为 0。 此属性用于性能优化。 int (System.Int32) DecrPoolSize OracleConnectionPool ODP.NET 属性。 指定未使用过多的已建立连接时关闭的...
Example Here’s a function that determines if a string is a valid ISBN number (it’s not foolproof, but it gets across the basic idea): CREATE OR REPLACE FUNCTION is_valid_isbn ( isbn_in IN VARCHAR2) RETURN BOOLEAN -- Ten digits separated by 4 hyphens IS l_isbn book.isbn%TYPE; BEG...