Merge语句
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Merge语句
概念&用处
用来合并update和insert语句
通过merge语句,根据一张表(原数据表,source table)对另外一张(目标表,target table)表进行查询,连接条件匹配上的进行update,无法匹配的执行INSERT。
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sqlplus / as sysdba
sqlplus scott/tiger
构建平台sql语句
create table KC
(
kch VARCHAR2(3) not null,
kcm VARCHAR2(16) not null,
kkxq NUMBER(1) not null,
xs NUMBER(2) not null,
xf NUMBER(1)
)
create table XS
(
xh VARCHAR2(6),
xm VARCHAR2(6),
zym VARCHAR2(6),
xb VARCHAR2(2),
cssj DATE,
zxf NUMBER(2),
bz VARCHAR2(20)
)
create table XS_KC
(
xh CHAR(6) not null,
kch CHAR(6) not null,
cj INTEGER,
xf NUMBER(2)
)
insert into KC (kch, kcm, kkxq, xs, xf)
values (\'001\', \'001\', 1, 11, 1);
insert into KC (kch, kcm, kkxq, xs, xf)
values (\'001\', \'001\', 1, 11, 1);
insert into XS (xh, xm, zym, xb, cssj, zxf, bz)
values (\'061101\', \'王林\', \'计算机\', \'男\', to_date(\'10-02-1986\', \'dd-mm-yyyy\'), 50, null);
insert into XS (xh, xm, zym, xb, cssj, zxf, bz)
values (\'101112\', \'李明\', \'计算机\', \'男\', to_date(\'30-01-1986\', \'dd-mm-yyyy\'), 36, null);
insert into XS (xh, xm, zym, xb, cssj, zxf, bz)
values (\'001\', \'张琼\', \'计算机\', null, null, 45, \'三好学生\');
insert into XS (xh, xm, zym, xb, cssj, zxf, bz)
values (\'121112\', \'王小二\', \'计算机\', \'男\', to_date(\'30-01-1986\', \'dd-mm-yyyy\'), 36, null);
insert into XS_KC (xh, kch, cj, xf)
values (\'061101\', \'101 \', 80, null);
insert into XS_KC (xh, kch, cj, xf)
values (\'061101\', \'102 \', 78, null);
insert into XS_KC (xh, kch, cj, xf)
values (\'061101\', \'206 \', 76, null);
insert into XS_KC (xh, kch, cj, xf)
values (\'061103\', \'101 \', 82, null);
insert into XS_KC (xh, kch, cj, xf)
values (\'061103\', \'102 \', 82, null);
insert into XS_KC (xh, kch, cj, xf)
values (\'061103\', \'206 \', 83, null);
insert into XS_KC (xh, kch, cj, xf)
values (\'061104\', \'101 \', 90, null);
insert into XS_KC (xh, kch, cj, xf)
values (\'061107\', \'101 \', 98, null);
insert into XS_KC (xh, kch, cj, xf)
values (\'061107\', \'102 \', 80, null);
commit;
使用MERGE语句XS1表中新增的数据插入表XS中:
create table xs1 as select * from xs;
insert into xs1(xh,xm,zym,xb,cssj,zxf) values(\'007\',\'test\',\'计算机\',\'男\',to_date(\'19900130\',\'YYYYMMDD\'),36)
--使用MERGE语句XS_JSJ表中新增的数据插入表XS中:
merge into xs a using xs1 b on(a.xh=b.xh)
when not matched then
insert(a.xh,a.xm,a.zym,a.xb,a.cssj,a.zxf)
values(b.xh,b.xm,b.zym,b.xb,b.cssj,b.zxf);
构建平台
create table PRODUCTS
(
PRODUCT_ID INTEGER,
PRODUCT_NAME VARCHAR2(60),
CATEGORY VARCHAR2(60)
);
create table NEWPRODUCTS
(
PRODUCT_ID INTEGER,
PRODUCT_NAME VARCHAR2(60),
CATEGORY VARCHAR2(60)
);
insert into PRODUCTS values (1501, \'VIVITAR 35MM\', \'ELECTRNCS\');
insert into PRODUCTS values (1502, \'OLYMPUS IS50\', \'ELECTRNCS\');
insert into PRODUCTS values (1600, \'PLAY GYM\', \'TOYS\');
insert into PRODUCTS values (1601, \'LAMAZE\', \'TOYS\');
insert into PRODUCTS values (1666, \'HARRY POTTER\', \'DVD\');
commit;
insert into NEWPRODUCTS values (1502, \'OLYMPUS CAMERA\', \'ELECTRNCS\');
insert into NEWPRODUCTS values (1601, \'LAMAZE\', \'TOYS\');
insert into NEWPRODUCTS values (1666, \'HARRY POTTER\', \'TOYS\');
insert into NEWPRODUCTS values (1700, \'WAIT INTERFACE\', \'BOOKS\');
commit;
products为目标表,newproducts为源表,则若产品号相匹配,根据源表信息修改目标表的产品名(product_name)和产品类别(category)
merge into products p
using newproducts np
on (p.product_id = np.product_id) when matched then
update set p.product_name=np.product_name, p.category=np.category;
若产品号不匹配,则根据源表将新的纪录添加到目标表
merge into products p using newproducts np on (p.product_id=np.product_id)
when not matched then insert values(np.product_id,np.product_name,np.category);
增删改
merge into products p using newproducts np on (p.product_id=np.product_id)
when matched then update set p.product_name= np.product_name,
p.category = np.category
delete where(p.category=\'ELECTRNCS\')
when not matched then insert values(np.product_id,np.product_name,np.category);
有的要别人来设定目标,有的给别人设定目标;
有的需要感情支持生活,有的需要意志支持生活。
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