The SQL-99 “WITH clause” is very confusing at first because the SQL statement does not begin with the word SELECT. Instead, we use the “WITH clause” to start our SQL query, defining the aggregations, which can then be named in the main query as if they were “real” tables: WITH...
WHERE NODE_LEVEL=1) 如果把WITH后面换成SELECT,一点问题没有,但UPDATE就是报错,好奇怪,难道WITH这种间接地写法不能用于UPDATA。 一种说法是:“with必须紧跟引用的select语句,而不是delete,update,merge等” http://www.itpub.net/thread-1585644-1-1.html 提到可以用MERGE: --wkc168 发表于 2012-3-2 13:2...
使用Oracle 'with'与使用表的行为不同。 'with' 是一种SQL语句,也被称为公共表表达式(CTE),它允许在查询中创建临时表,以便在同一查询中多次引用。与使用表不同,'with' 语句不会在数据库中创建永久表。 具体来说,使用Oracle 'with' 的行为有以下几个方面的不同: ...
UPDATEt1 t1_alias SET(table_name, tablespace_name)=( SELECT table_name, tablespace_name FROM t2 t2_alias WHERE t1_alias.table_name = t2_alias.table_name); SELECT * FROM t1; Nested Table Update See Nested Tables page Update With Returning Clause Returning Clause demoUPDATE (<SELECT Statemen...
SQL> --Modify multiple rows with a single UPDATE statement; SQL> SQL> SQL> UPDATE Employee 2 SET City ='L.A.' 3 WHERE City = 'New York'; 2 rows updated. SQL> SQL> select * from employee; ID FIRST_NAME LAST_NAME START_DAT END_DATE SALARY CITY DESCRIPTION ...
Select_statement:select语句 WITH CHECK OPTION :此选项指定只能插入或更新视图可以访问的行。术语constraint表示为CHECK OPTION约束指定的名称。 WITH READ ONLY:此选项保证不能在此视图上执行任何修改操作。 3、DML语句和复杂视图 DML语句是指用于修改数据的insert、delete和update语句。因为视图是一个虚拟的表,所以这些...
描述:当UPDATE或DELETE操作的事务在提交之前,如果其缓存住的数据发生了变化,该提示使得事务被重新启动———这可能会导致表上的触发器被再次执行; HELLODBA.COM>-- 会话 1 HELLODBA.COM>create table t(a number primary key); Table created. HELLODBA.COM>insert into t values(1); 1 ...
UPDATE :Use to Edit Existing Rows in tables. DELETE :Use to Delete Rows from tables. MERGE :Use to Update or Insert Rows depending on condition. Insert Use the Insert Statement to Add records to existing Tables. Examples. To add a new row to an emp table. ...
从名字解析角度看,WITH子句PL/SQL声明部分定义的函数比当前模式中其他同名对象优先级要高。 3. WITH子句中的过程 即使不被使用,我们也可以在声明部分定义过程。 SET SERVEROUTPUT ON WITH PROCEDURE with_procedure(p_id IN NUMBER) IS BEGIN DBMS_OUTPUT.put_line('p_id=' || p_id); ...
The following statement updatesHunold'shire date using theTO_DATEfunction with the format mask 'YYYY MM DD' to convert the character string '1998 05 20' to aDATEvalue: UPDATE employeesSET hire_date = TO_DATE('1998 05 20','YYYY MM DD')WHERE last_name = 'Hunold'; ...