UPDATE (SELECT A.NAME ANAME,B.NAME BNAME FROM A,B WHERE A.ID=B.ID) 代码语言:txt AI代码解释 SET ANAME=BNAME; 例如: 代码语言:txt AI代码解释 UPDATE tablea a 代码语言:txt AI代码解释 SET a.fieldforupdate = (SELECT b.fieldsource FROM tableb b WHERE a.keyfield = b.keyfield) 代码...
对于select语句,我们可以通过join/outer join来关联多个表;但是对于update语句,是不能直接通过join/outer join来关联多表数据的,这里仅针对PostgreSQL。 或者说,在PostgreSQL中,就算使用update+join不会报错,但join的那部分其实是没任何效果的,如下所示: 1 2 3 4 5 6 7 8 update a set value = 'test' from ...
ora_dict_obj_name, -- 与触发器相关的函数 ora_dict_obj_type, sysdate); end; / 3. 测试 create table drop_me(a number); create view drop_me_view as select *from drop_me; drop view drop_me_view; drop table drop_me; select *from droped_objects 禁用和启用触发器 alter trigger <trigg...
1 --DDL2CREATE TABLE student (3id NUMBER NOT NULL ,4 name VARCHAR2(255BYTE) NULL ,5 sex VARCHAR2(255BYTE) NULL6)78ALTER TABLE student ADD CHECK (id IS NOT NULL);910 --DML11 INSERT INTO student VALUES ('1','zhangsan','boy');12 INSERT INTO student VALUES ('2','lisi','girl')...
create table testb as select * from dba_objects where rownum<=30000; --数据源表关联字段上要有索引, 可以先不建, 看看效率 create unique index UIDX_TESTA_OBJECT_ID on testa(object_id); 1. 2. 3. 4. 5. 6. 7. 8. 二、 各种关联update写法 ...
oracle update用法 注:update操作时,条件必须注意。不写where即为更新全表,不想更新的会被赋空值。 单表更新:update tablename set col1=value where col2='value2'; 多表关联更新:update a set a.col1=(select b.col1 from b where a.col2=b.col2)where exists(select * from b where a.col2=b...
Table created. SQL> select table_name,degree from user_tables; TABLE_NAME DEGREE --- --- TAB_3 1 4. 优先级(并行度覆盖) 官方说明 If you are sure you want to execute in parallel and want to avoid setting the DOP for a table or modifying the queries involved, you can force parallelis...
UPDATEtable-Name[[AS] correlation-Name] SETcolumn-Name=Value[ ,column-Name=Value} ]* [WHERE clause] | UPDATEtable-NameSETcolumn-Name=Value[ ,column-Name=Value]*WHERE CURRENT OF} whereValueis defined as follows: Expression| DEFAULT The first syntactical form, called a searched update, updates...
UPDATE [Owner.]TableNameSETColumnName=Subquery[WHERESearchCondition] または UPDATE [Owner.]TableNameSET (ColumnName[,…])=Subquery[WHERESearchCondition] パラメータ UPDATE文には、次のパラメータがあります。 説明 結合更新のSET句内で副問合せを使用しても、更新されるターゲット表の行数は削減さ...
CREATE TABLE greenplum_table (uuid VARCHAR(255),data VARCHAR(255)) WITH ('connector' = 'jdbc','url' = 'jdbc:postgresql://your_greenplum_host:5432/your_database','username' = 'your_username','password' = 'your_password','table-name' = 'your_table_name'); ...