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
我刚刚做了marc_s“presentation ready”:
SELECT
c.name 'Column Name',
t.name 'Data type',
IIF(t.name = 'nvarchar', c.max_length / 2, c.max_length) 'Max Length',
c.precision 'Precision',
c.scale 'Scale',
IIF(c.is_nullable = 0, 'No', 'Yes') 'Nullable',
IIF(ISNULL(i.is_primary_key, 0) = 0, 'No', 'Yes') 'Primary Key'
FROM
sys.columns c
INNER JOIN
sys.types t ON c.user_type_id = t.user_type_id
LEFT OUTER JOIN
sys.index_columns ic ON ic.object_id = c.object_id AND ic.column_id = c.column_id
LEFT OUTER JOIN
sys.indexes i ON ic.object_id = i.object_id AND ic.index_id = i.index_id
WHERE
c.object_id = OBJECT_ID('YourTableName')
其他回答
为了确保获得正确的长度,需要将unicode类型视为一种特殊情况。参见下面的代码。
更多信息请参见:https://msdn.microsoft.com/en-us/library/ms176106.aspx
SELECT
c.name 'Column Name',
t.name,
t.name +
CASE WHEN t.name IN ('char', 'varchar','nchar','nvarchar') THEN '('+
CASE WHEN c.max_length=-1 THEN 'MAX'
ELSE CONVERT(VARCHAR(4),
CASE WHEN t.name IN ('nchar','nvarchar')
THEN c.max_length/2 ELSE c.max_length END )
END +')'
WHEN t.name IN ('decimal','numeric')
THEN '('+ CONVERT(VARCHAR(4),c.precision)+','
+ CONVERT(VARCHAR(4),c.Scale)+')'
ELSE '' END
as "DDL name",
c.max_length 'Max Length in Bytes',
c.precision ,
c.scale ,
c.is_nullable,
ISNULL(i.is_primary_key, 0) 'Primary Key'
FROM
sys.columns c
INNER JOIN
sys.types t ON c.user_type_id = t.user_type_id
LEFT OUTER JOIN
sys.index_columns ic ON ic.object_id = c.object_id AND ic.column_id = c.column_id
LEFT OUTER JOIN
sys.indexes i ON ic.object_id = i.object_id AND ic.index_id = i.index_id
WHERE
c.object_id = OBJECT_ID('YourTableName')
在查询编辑器中选择表名并按Alt+F1,它将带来表的所有信息。
Marc_s的答案很好,但如果主键列出现在其他索引中,这些列会出现不止一次,那么它就有一个缺陷。如。
演示:
create table dbo.DummyTable
(
id int not null identity(0,1) primary key,
Msg varchar(80) null
);
create index NC_DummyTable_id ON DummyTable(id);
下面是我用来解决这个问题的存储过程:
create or alter procedure dbo.GetTableColumns
(
@schemaname nvarchar(128),
@tablename nvarchar(128)
)
AS
BEGIN
SET NOCOUNT ON;
with ctePKCols as
(
select
i.object_id,
ic.column_id
from
sys.indexes i
join sys.index_columns ic ON i.object_id = ic.object_id AND i.index_id = ic.index_id
where
i.is_primary_key = 1
)
SELECT
c.name AS column_name,
t.name AS typename,
c.max_length AS MaxLength,
c.precision,
c.scale,
c.is_nullable,
is_primary_key = CASE WHEN ct.column_id IS NOT NULL THEN 1 ELSE 0 END
FROM
sys.columns c
JOIN sys.types t ON t.user_type_id = c.user_type_id
LEFT JOIN ctePKCols ct ON ct.column_id = c.column_id AND ct.object_id = c.object_id
WHERE
c.object_ID = OBJECT_ID(quotename(@schemaname) + '.' + quotename(@tablename))
END
GO
exec dbo.GetTableColumns 'dbo', 'DummyTable'
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