我需要在SQL server上编写一个查询,以获得特定表中的列列表,其相关数据类型(长度)以及它们是否不为空。我已经做到了这么多。
但现在我还需要得到,在同一个表中,对一个列- TRUE,如果该列是一个主键。
我该怎么做呢?
我的期望输出是:
Column name | Data type | Length | isnull | Pk
我需要在SQL server上编写一个查询,以获得特定表中的列列表,其相关数据类型(长度)以及它们是否不为空。我已经做到了这么多。
但现在我还需要得到,在同一个表中,对一个列- TRUE,如果该列是一个主键。
我该怎么做呢?
我的期望输出是:
Column name | Data type | Length | isnull | Pk
当前回答
IF EXISTS (SELECT 1 FROM INFORMATION_SCHEMA.TABLES
WHERE TABLE_TYPE = 'BASE TABLE' AND TABLE_NAME = 'Table')
BEGIN
SELECT COLS.COLUMN_NAME, COLS.DATA_TYPE, COLS.CHARACTER_MAXIMUM_LENGTH,
(SELECT 'Yes' FROM INFORMATION_SCHEMA.TABLE_CONSTRAINTS TC JOIN INFORMATION_SCHEMA.KEY_COLUMN_USAGE KCU
ON COLS.TABLE_NAME = TC.TABLE_NAME
AND TC.CONSTRAINT_TYPE = 'PRIMARY KEY'
AND KCU.TABLE_NAME = TC.TABLE_NAME
AND KCU.CONSTRAINT_NAME = TC.CONSTRAINT_NAME
AND KCU.COLUMN_NAME = COLS.COLUMN_NAME) AS KeyX
FROM INFORMATION_SCHEMA.COLUMNS COLS WHERE TABLE_NAME = 'Table' ORDER BY KeyX DESC, COLUMN_NAME
END
其他回答
查找数据类型和长度的组合结果,并以“NULL”和“非空”的形式为空。
SELECT c.name AS 'Column Name',
t.name + '(' + cast(c.max_length as varchar(50)) + ')' As 'DataType',
case
WHEN c.is_nullable = 0 then 'null' else 'not null'
END AS 'Constraint'
FROM sys.columns c
JOIN sys.types t
ON c.user_type_id = t.user_type_id
WHERE c.object_id = Object_id('TableName')
你会发现结果如下所示。
谢谢你!
试试这个:
select COLUMN_NAME, DATA_TYPE, CHARACTER_MAXIMUM_LENGTH, IS_NULLABLE
from INFORMATION_SCHEMA.COLUMNS IC
where TABLE_NAME = 'tablename' and COLUMN_NAME = 'columnname'
抛出了另一种在SQL server中解决问题的方法。 我的小脚本在这里应该返回列名,数据类型,是空的,约束和索引名称。 您还可以包括任何额外的列,如精度,比例… (你需要用你的数据库名、Schema name和Table name替换数据库名) .返回列的顺序与从'select * from table'中返回列的顺序相同
USE DBA -- Replace Database Name with yours
DECLARE @SCHEMA VARCHAR(MAX)
DECLARE @TABLE_NAME VARCHAR(MAX)
DECLARE @SCHEMA_TABLE_NAME VARCHAR(MAX)
SET @SCHEMA = REPLACE(REPLACE('[SCHEMA NAME]', '[', ''), ']', '')--Replace Schema Name with yours
SET @TABLE_NAME = REPLACE(REPLACE('[TABLE NAME]', '[', ''), ']', '') --' Replace Table Name with yours
SET @SCHEMA_TABLE_NAME = @SCHEMA + '.' + @TABLE_NAME;
WITH SchemaColumns
AS (
SELECT C.COLUMN_NAME,
IS_NULLABLE,
DATA_TYPE,
CHARACTER_MAXIMUM_LENGTH,
C.ORDINAL_POSITION
FROM INFORMATION_SCHEMA.COLUMNS AS C
WHERE C.TABLE_SCHEMA = @SCHEMA
AND C.TABLE_NAME = @TABLE_NAME
),
SchemaConstraints
AS (
SELECT CN.COLUMN_NAME,
CC.CONSTRAINT_TYPE
FROM INFORMATION_SCHEMA.TABLE_CONSTRAINTS AS CC
INNER JOIN INFORMATION_SCHEMA.CONSTRAINT_COLUMN_USAGE AS CN ON CC.CONSTRAINT_NAME = CC.CONSTRAINT_NAME
WHERE CC.TABLE_SCHEMA = @SCHEMA
AND CC.TABLE_NAME = @TABLE_NAME
),
SchemaIndex
AS (
SELECT I.name AS index_name,
COL_NAME(IC.object_id, IC.column_id) AS column_name,
IC.index_column_id,
IC.key_ordinal,
IC.is_included_column
FROM sys.indexes AS i
INNER JOIN sys.index_columns AS IC ON I.object_id = IC.object_id
AND I.index_id = IC.index_id
WHERE I.object_id = OBJECT_ID(@SCHEMA_TABLE_NAME)
)
SELECT ISNULL(SchemaColumns.COLUMN_NAME, '') "Column Name",
CASE
WHEN SchemaColumns.CHARACTER_MAXIMUM_LENGTH IS NULL
THEN UPPER(ISNULL(SchemaColumns.DATA_TYPE, ''))
ELSE CONCAT (
UPPER(ISNULL(SchemaColumns.DATA_TYPE, '')),
'(',
CAST(SchemaColumns.CHARACTER_MAXIMUM_LENGTH AS VARCHAR(50)),
')'
)
END "Data Type",
SchemaColumns.IS_NULLABLE "Is Nullable",
ISNULL(SchemaConstraints.CONSTRAINT_TYPE, '-') "Constraints",
ISNULL(STRING_AGG(CONVERT(NVARCHAR(max), SchemaIndex.INDEX_NAME), CHAR(13)), '-') "Indexes Names"
FROM SchemaColumns
LEFT JOIN SchemaConstraints ON SchemaConstraints.COLUMN_NAME = SchemaColumns.COLUMN_NAME
LEFT JOIN SchemaIndex ON SchemaColumns.COLUMN_NAME = SchemaIndex.COLUMN_NAME
GROUP BY SchemaColumns.COLUMN_NAME,
SchemaColumns.DATA_TYPE,
SchemaColumns.CHARACTER_MAXIMUM_LENGTH,
SchemaColumns.IS_NULLABLE,
SchemaConstraints.CONSTRAINT_TYPE,
SchemaColumns.ORDINAL_POSITION
ORDER BY SchemaColumns.ORDINAL_POSITION
查询:执行sp_description _first_result_set并选择年收入 [DB_NAME]。[DBO]。(员工)”
注意:在某些ide中选择n之前是工作的,或者在某些ide中没有选择n是工作的
在SQL 2012中,你可以使用:
EXEC sp_describe_first_result_set N'SELECT * FROM [TableName]'
这将为您提供列名及其属性。