I need to run some SQL which will return my columns from a table.
I need to use these columns in an INSERT statement.
I could run:
select *
from information_schema.columns
where table_name = 'tableName'
but I need to print something like this:
[table.custid], [table.address], [table.name]
I thought you may need them to use for example with dynamic sql, you can get the list of column in the format you want as:
DECLARE #ColNames VARCHAR(1000)
SELECT #ColNames = COALESCE(#ColNames+', ', '') + QUOTENAME('tableName.'+NAME,'[')
FROM SYS.COLUMNS
WHERE OBJECT_id = OBJECT_id('tableName')
SELECT #ColNames
Edit summary: adding tablename prefix to columns as wanted in question
Try this
SELECT * FROM SYS.COLUMNS
WHERE object_id = OBJECT_ID('dbo.TableName')
DECLARE #sql as VARCHAR(8000)
SET #sql = ' '
SELECT #sql += '[table.'+[Name] + '],' FROM SYS.COLUMNS
WHERE object_id = OBJECT_ID('dbo.TableName')
PRINT(#sql)
Related
I need to prepare a dynamic query to find the length of all the rows in a column in sql server. let say if there are 10 columns for a table with 100 rows. I need to find the row length for each column dynamically.
Assuming that your all columns are string columns, though len function should work anyways.
-- replace 'mytable' with the actual table name
declare #tableName nvarchar(128) = 'mytable';
declare #queryToRun nvarchar(max) = '';
-- IMPORTANT: following query is putting each column name as len_columnName
select #queryToRun = #queryToRun + ', len([' + c.name + ']) as [len_' + c.name + ']
'
from sys.tables as t
inner join sys.columns as c on t.object_id = c.object_id
where t.name = #tableName
-- removing the first comma
set #queryToRun = SUBSTRING(#queryToRun, 2, len(#queryToRun) - 1);
-- creating the query with dynamic column names
set #queryToRun = 'select ' + #queryToRun + ' from ' + #tableName;
--print #queryToRun
exec (#queryToRun)
you can use sys.tables and sys.all_columns
declare #Sql nvarchar(max)='select '
select #Sql=#sql+'Sum(len('+QUOTENAME(c.name)+')) as Len'+QUOTENAME(c.name)+',' from sys.tables t join sys.all_columns c on t.object_id=c.object_id
where t.Name='YourTableName'
set #Sql = left(#Sql,len(#sql)-1)+' from YourTableName'
select #Sql
Try this Script you will get data length of each columns in table dynamically
IF OBJECT_ID('dbo.LenghtOfRows')IS NOT NULL
DROP TABLE LenghtOfRows
CREATE TABLE LenghtOfRows (
Id Int IDENTITY,
Sqlode nvarchar(max)
)
DECLARE #SQL NVARCHAR(max),
#MinId INT,
#MaxId INT,
#tableName Varchar(100) ='StudentLabExamScore', --Give Table name here
#GetSQL NVARCHAR(max)
SET #SQL = 'SELECT ''SELECT DATALENGTH(''+COLUMN_NAME+'') As Len_'' +COLUMN_NAME +'' FROM ''+TABLE_NAME
FROM INFORMATION_SCHEMA.COLUMNS
WHERE TABLE_NAME = '''+#tableName+''''
PRINT #SQL
INSERT INTO LenghtOfRows(Sqlode)
EXEC ( #SQL)
SELECT #MinId = MIN(Id) from LenghtOfRows
SELECT #MaxId = MAX(Id) from LenghtOfRows
WHILE (#MInId <=#MaxId)
BEGIN
SELECT #GetSQL= Sqlode FROM LenghtOfRows WHERE id=#MInId
EXEC (#GetSQL)
PRINT #GetSQL
SET #MInId=#MInId+1
END
I need to create a dynamic sql query in order to return all values in the first column of a table. The table's name needs to be a variable #tableName ( i will run this query for multiple tables depending on several conditions). Also, i don't know exactly the first column's name but it is formed out of Id_#tableName .
I need something like below but written dinamically:
select
(select column_name from INFORMATION_SCHEMA.columns where table_Name= #tableName and ordinal_position=1)
from #tableName
Could you please help me? Thank you in advance!
USE AdventureWorks;
GO
DECLARE #ObjectName SYSNAME = 'Sales.SalesOrderHeader';
DECLARE #SQL NVARCHAR(MAX);
SELECT
#SQL = 'SELECT ' + QUOTENAME(name) + ' FROM ' + #ObjectName
FROM
sys.columns
WHERE
object_id = OBJECT_ID(#ObjectName)
AND column_id = 1;
EXEC sp_executesql #SQL;
I have a question about select in SQL Server.
First I'm getting columns name from temp table with proper type query looks like this:
select
sc.name, st.name
from
tempdb.sys.columns sc
left join
sys.types st on sc.system_type_id = st.system_type_id
where
object_id = object_id('tempdb..#_tmpDocs')
and st.name in ('char', 'varchar', 'nvarchar')
Result is a list of columns with type I want, but next I want to select those columns in different query so if ill save result from above query into temp table with name #columns with it be possible to do something like
select (select * from #columns) from target_table
Here's a dynamic sql that will do what you need:
CREATE TABLE #_tmpDocs (id INT, x CHAR(10), y VARCHAR(100))
DECLARE #cols NVARCHAR(1000)
DECLARE #sql NVARCHAR(1000)
SELECT #cols = COALESCE(#cols + ',', '') + QUOTENAME(SC.name)
FROM tempdb.sys.columns sc
LEFT JOIN sys.types st ON sc.system_type_id = st.system_type_id
WHERE object_id = OBJECT_ID('tempdb..#_tmpDocs')
AND st.name IN ( 'char', 'varchar', 'nvarchar' )
SET #sql = 'select ' + #cols + ' from #_tmpDocs'
PRINT #sql
EXEC (#sql)
EXEC sp_executesql #sql
Chose between EXEC (#sql) and EXEC sp_executesql #sql based on you needs - see here to get an idea of what each is doing.
I don't think you can reference columns dynamically in SQL like that. Just doing a pure sql version, it won't work:
declare #x varchar(50) = 'MyColumn';
select #x from dbo.MyTable
You'll need to use dynamic sql, and build a string:
declare #x nvarchar(50) = 'MyColumn';
declare #y nvarchar(250) = 'select ' + #x + ' from dbo.MyTable';
EXECUTE sp_executesql #y
So in your case you may want to loop through your return result or otherwise turn it into a string of column names that can be concatenated to a larger query (like above).
Did you try this?
SELECT *
FROM tempdb.sys.columns
WHERE object_id = object_id('tempdb..#columns');
I know that I can search for a term in one column in a table in t-sql by using like %termToFind%. And I know I can get all columns in a table with this:
SELECT *
FROM MyDataBaseName.INFORMATION_SCHEMA.COLUMNS
WHERE TABLE_NAME = N'MyTableName`
How can I perform a like comprparison on each of the columns of a table? I have a very large table so I can't just spell out LIKE for each column.
As always, I'll suggest xml for this (I'd suggest JSON if SQL Server had native support for it :) ). You can try to use this query, though it could perform not so well on large number of rows:
;with cte as (
select
*,
(select t.* for xml raw('data'), type) as data
from test as t
)
select *
from cte
where data.exist('data/#*[local-name() != "id" and contains(., sql:variable("#search"))]') = 1
see sql fiddle demo for more detailed example.
Important note by Alexander Fedorenko in comments: it should be understood that contains function is case-sensitive and uses xQuery default Unicode code point collation for the string comparison.
More general way would be to use dynamic SQL solution:
declare #search nvarchar(max)
declare #stmt nvarchar(max)
select #stmt = isnull(#stmt + ' or ', '') + quotename(name) + ' like #search'
from sys.columns as c
where c.[object_id] = object_id('dbo.test')
--
-- also possible
--
-- select #stmt = isnull(#stmt + ' or ', '') + quotename(column_name) + ' like #search'
-- from INFORMATION_SCHEMA.COLUMNS
-- where TABLE_NAME = 'test'
select #stmt = 'select * from test where ' + #stmt
exec sp_executesql
#stmt = #stmt,
#params = N'#search nvarchar(max)',
#search = #search
sql fiddle demo
I'd use dynamic SQL here.
Full credit - this answer was initially posted by another user, and deleted. I think it's a good answer so I'm re-adding it.
DECLARE #sql NVARCHAR(MAX);
DECLARE #table NVARCHAR(50);
DECLARE #term NVARCHAR(50);
SET #term = '%term to find%';
SET #table = 'TableName';
SET #sql = 'SELECT * FROM ' + #table + ' WHERE '
SELECT #sql = #sql + COALESCE('CAST('+ column_name
+ ' as NVARCHAR(MAX)) like N''' + #term + ''' OR ', '')
FROM INFORMATION_SCHEMA.COLUMNS WHERE [TABLE_NAME] = #table
SET #sql = #sql + ' 1 = 0'
SELECT #sql
EXEC sp_executesql #sql
The XML answer is cleaner (I prefer dynamic SQL only when necessary) but the benefit of this is that it will utilize any index you have on your table, and there is no overhead in constructing the XML CTE for querying.
In case someone is looking for PostgreSQL solution:
SELECT * FROM table_name WHERE position('your_value' IN (table_name.*)::text)>0
will select all records that have 'your_value' in any column. Didn't try this with any other database.
Unfortunately this works as combining all columns to a text string and then searches for a value in that string, so I don't know a way to make it match "whole cell" only. It will always match if any part of any cell matches 'your_value'.
I have a table with column names a1,a2...,b1.b2....
How can I select all those with column names like a%?
This will get you the list
select * from information_schema.columns
where table_name='table1' and column_name like 'a%'
If you want to use that to construct a query, you could do something like this:
declare #sql nvarchar(max)
set #sql = 'select '
select #sql = #sql + '[' + column_name +'],'
from information_schema.columns
where table_name='table1' and column_name like 'a%'
set #sql = left(#sql,len(#sql)-1) -- remove trailing comma
set #sql = #sql + ' from table1'
exec sp_executesql #sql
Note that the above is written for SQL Server.
You need to use view INFORMATION_SCHEMA.COLUMNS
select COLUMN_NAME from INFORMATION_SCHEMA.COLUMNS where TABLE_NAME = my_table_name AND COLUMN_NAME like 'a%'
TO inline rows you can use PIVOT and for execution EXEC() function.
This will show you the table name and column name
select table_name,column_name from information_schema.columns
where column_name like '%breakfast%'
SELECT * FROM SysColumns WHERE Name like 'a%'
Will get you a list of columns, you will want to filter more to restrict it to your target table
From there you can construct some ad-hoc sql
Here is a nice way to display the information that you want:
SELECT B.table_catalog as 'Database_Name',
B.table_name as 'Table_Name',
stuff((select ', ' + A.column_name
from INFORMATION_SCHEMA.COLUMNS A
where A.Table_name = B.Table_Name
FOR XML PATH(''),TYPE).value('(./text())[1]','NVARCHAR(MAX)')
, 1, 2, '') as 'Columns'
FROM INFORMATION_SCHEMA.COLUMNS B
WHERE B.TABLE_NAME like '%%'
AND B.COLUMN_NAME like '%%'
GROUP BY B.Table_Catalog, B.Table_Name
Order by 1 asc
Add anything between either '%%' in the main select to narrow down what tables and/or column names you want.
You cannot with standard SQL. Column names are not treated like data in SQL.
If you use a SQL engine that has, say, meta-data tables storing column names, types, etc. you may select on that table instead.
Blorgbeard had a great answer for SQL server. If you have a MySQL server like mine then the following will allow you to select the information from columns where the name is like some key phrase. You just have to substitute the table name, database name, and keyword.
SET #columnnames = (SELECT concat("`",GROUP_CONCAT(`COLUMN_NAME` SEPARATOR "`, `"),"`")
FROM `INFORMATION_SCHEMA`.`COLUMNS`
WHERE `TABLE_SCHEMA`='your_database'
AND `TABLE_NAME`='your_table'
AND COLUMN_NAME LIKE "%keyword%");
SET #burrito = CONCAT("SELECT ",#columnnames," FROM your_table");
PREPARE result FROM #burrito;
EXECUTE result;
Thank you #Blorgbeard for the genious idea.
By the way Blorgbeard's query was not working for me so I edited it:
DECLARE #Table_Name as VARCHAR(50) SET #Table_Name = 'MyTable' -- put here you table name
DECLARE #Column_Like as VARCHAR(20) SET #Column_Like = '%something%' -- put here you element
DECLARE #sql NVARCHAR(MAX) SET #sql = 'select '
SELECT #sql = #sql + '[' + sys.columns.name + '],'
FROM sys.columns
JOIN sys.tables ON sys.columns.object_id = tables.object_id
WHERE sys.columns.name like #Column_Like
and sys.tables.name = #Table_Name
SET #sql = left(#sql,len(#sql)-1) -- remove trailing comma
SET #sql = #sql + ' from ' + #Table_Name
EXEC sp_executesql #sql