复制表结构和数据SQL语句
1.复制表结构及数据到新表
CREATE TABLE新表SELECt * FROM旧表
2.只复制表结构到新表
CREATE TABLE新表SELECt * FROM旧表WHERe1=2
即:让WHERe条件不成⽴.
CREATE TABLE新表 LIKE 旧表
3.复制旧表的数据到新表(假设两个表结构⼀样)
INSERT INTO新表SELECt * FROM旧表
4.复制旧表的数据到新表(假设两个表结构不⼀样)
INSERT INTO新表(字段1,字段2,.......)SELECt字段1,字段2,...... FROM旧表
SQL SERVER 2008
insert into b(a, b, c) select d,e,f from b;
说明：复制表(只复制结构,源表名：a 新表名：b)
SQL: select * into b from a where 1<>1
说明：拷贝表(拷贝数据,源表名：a ⽬标表名：b)
SQL: insert into b(a, b, c) select d,e,f from b;
说明：显⽰⽂章、提交⼈和最后回复时间
SQL: select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b
说明：外连接查询(表名1：a 表名2：b)
SQL: select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c
说明：⽇程安排提前五分钟提醒
SQL: select * from ⽇程安排 where datediff('minute',f开始时间,getdate())>5
说明：两张关联表，删除主表中已经在副表中没有的信息
从数据库中去⼀年的各单位电话费统计(电话费定额贺电化肥清单两个表来源）
SQL:
SELECt a.userper, a.tel, a.standfee, TO_CHAr(a.telfeedate, 'yyyy') AS telyear,
SUM(decode(TO_CHAr(a.telfeedate, 'mm'), '01', a.factration)) AS JAN,
SUM(decode(TO_CHAr(a.telfeedate, 'mm'), '02', a.factration)) AS FRI,
SUM(decode(TO_CHAr(a.telfeedate, 'mm'), '03', a.factration)) AS MAR,
SUM(decode(TO_CHAr(a.telfeedate, 'mm'), '04', a.factration)) AS APR,
SUM(decode(TO_CHAr(a.telfeedate, 'mm'), '05', a.factration)) AS MAY,
SUM(decode(TO_CHAr(a.telfeedate, 'mm'), '06', a.factration)) AS JUE,
SUM(decode(TO_CHAr(a.telfeedate, 'mm'), '07', a.factration)) AS JUL,
SUM(decode(TO_CHAr(a.telfeedate, 'mm'), '08', a.factration)) AS AGU,
SUM(decode(TO_CHAr(a.telfeedate, 'mm'), '09', a.factration)) AS SEP,
SUM(decode(TO_CHAr(a.telfeedate, 'mm'), '10', a.factration)) AS OCT,
SUM(decode(TO_CHAr(a.telfeedate, 'mm'), '11', a.factration)) AS NOV,
SUM(decode(TO_CHAr(a.telfeedate, 'mm'), '12', a.factration)) AS DEC
FROM (SELECt a.userper, a.tel, a.standfee, b.telfeedate, b.factration
FROM TELFEESTAND a, TELFEE b
WHERe a.tel = b.telfax) a
GROUP BY a.userper, a.tel, a.standfee, TO_CHAr(a.telfeedate, 'yyyy')
说明：四表联查问题：
SQL: select * from a left inner join b on a.a=b.b right inner join c on a.a=c.c inner join d on a.a=d.d where .....
说明：得到表中最⼩的未使⽤的ID号
SQL:
SELECt (CASE WHEN EXISTS(SELECT * FROM Handle b WHERe b.HandleID = 1) THEN MIN(HandleID) + 1 ELSE 1 END) as HandleID FROM Handle
WHERe NOT HandleID IN (SELECt a.HandleID - 1 FROM Handle
