sql server 表结构数据字典的sql语句
SELECT TOP (100) PERCENT
CASE WHEN a.colorder = 1 THEN d .name ELSE '' END AS 表名, CASE WHEN a.colorder = 1 THEN isnull(f.value, '')
ELSE '' END AS 表说明, a.colorder AS 字段序号, a.name AS 字段名, CASE WHEN COLUMNPROPERTY(a.id, a.name, 'IsIdentity')
= 1 THEN '√' ELSE '' END AS 标识, CASE WHEN EXISTS
(SELECT 1 from dbo.sysindexes si INNER JOIN
dbo.sysindexkeys sik ON si.id = sik.id AND si.indid = sik.indid INNER JOIN
dbo.syscolumns sc ON sc.id = sik.id AND sc.colid = sik.colid INNER JOIN
dbo.sysobjects so ON so.name = so.name AND so.xtype = 'PK'
WHERE sc.id = a.id AND sc.colid = a.colid) THEN '√' ELSE '' END AS 主键, b.name AS 类型, a.length AS 长度, COLUMNPROPERTY(a.id, a.name,
'PRECISION') AS 精度, ISNULL(COLUMNPROPERTY(a.id, a.name, 'Scale'), 0) AS 小数位数,
CASE WHEN a.isnullable = 1 THEN '√' ELSE '' END AS 允许空, ISNULL(e.text, '') AS 默认值, ISNULL(g.value, '') AS 字段说明, d.crdate AS 创建时间,
CASE WHEN a.colorder = 1 THEN d .refdate ELSE NULL END AS 更改时间
from dbo.syscolumns AS a LEFT OUTER JOIN
dbo.systypes AS b ON a.xtype = b.xusertype INNER JOIN
dbo.sysobjects AS d ON a.id = d.id AND d.xtype = 'U' AND d.status >= 0 LEFT OUTER JOIN
dbo.syscomments AS e ON a.cdefault = e.id LEFT OUTER JOIN
sys.extended_properties AS g ON a.id = g.major_id AND a.colid = g.minor_id LEFT OUTER JOIN
sys.extended_properties AS f ON d.id = f.major_id AND f.minor_id = 0
ORDER BY d.name, 字段序号
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Update Channel set Unit ='mg' ,
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SafetyDownThreshold='10'
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and SensorCode='001' and Supplement='N'
set ： ','
where: and ......
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begin
for item in (select * from user_constraints a where a.constraint_type = 'R') loop
execute immediate 'alter table ' || item.table_name || ' disable constraint ' || item.constraint_name;
end loop;
end;
/ ......
SQL函数 left()、charindex()的使用
1、left()
LEFT (<character_expression>， <integer_expression>)
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