This question already has answers here:
What is the SQL to change the field length of a table column in SQL Server
(6 answers)
Closed 9 years ago.
I am looking to find out how to alter a fields properties contained in an SQL Server 2008 table via an SQL script.
I'm looking to change the 'Length' property specifically.
Does anybody know how to do this?
Thanks
So, let's say you have this table:
CREATE TABLE YourTable(Col1 VARCHAR(10))
And you want to change Col1 to VARCHAR(20). What you need to do is this:
ALTER TABLE YourTable
ALTER COLUMN Col1 VARCHAR(20)
That'll work without problems since the length of the column got bigger. If you wanted to change it to VARCHAR(5), then you'll first gonna need to make sure that there are not values with more chars on your column, otherwise that ALTER TABLE will fail.
Related
This question already has answers here:
Find a string by searching all tables in SQL Server
(12 answers)
Closed 1 year ago.
I have a lot of tables inside some database of SQL Server and I think that some of those tables have some specific column that, I want to check if it exists and also see the values inside, if it actually exists.
I guess that the column was named like: ‘’Status’’
Please, consider that I don't have any idea about what are the values that maybe exist inside of this supposed column or even the kind of it.
Database name: PrincipalGroup
I won't say the name of the tables, because I don’t think it's feasible to write all the tables in this query, because there are many.
So, the point is: how can I query this by the easiest and simplest way?
You can try the following query that will produce a list of SQL statements you can then execute to "see the values inside" each table that contains the column named Status, and obviously tweak to your specific requirements.
select Concat('select distinct ', QUOTENAME(table_name, ''''), ' , [Status] from ', QuoteName(table_name))
from INFORMATION_SCHEMA.COLUMNS
where COLUMN_NAME = 'Status'
This question already has answers here:
How can we figure out that a column in my oracle table is being populated/updated by a trigger of another table?
(3 answers)
Closed 5 years ago.
How to check whether a particular column of a table is used in any other object or not in Oracle? For example I have a table EMPLOYEE which has a column BONUS. I need to check whether this column of this table is been used by any other objects like View, Package etc in the database.
You can try the following SQL to check for the table and column used within the object definition
SELECT 1
FROM all_source
WHERE type IN ('PROCEDURE','PACKAGE BODY','FUNCTION')
AND text LIKE '%EMPLOYEE%'
AND text LIKE '%BONUS%';
This question already has answers here:
Comparing dates stored as varchar
(3 answers)
Closed 3 years ago.
In design time we have given [DOJInGovrService] field as varchar datatype.
now when we are trying order by this parameter(DOJInGovrService) in ascending order it is not giving the desired result.
I know it is datatype problem but I can't change the datatype now as data is already entered.
SELECT ED.class,
ED.CurrentOfficePlace,
ED.DOB,
ED.DOJInCurrentOff,
ED.DOJInGovrService,
ED.DOJInSamvarg,
ED.EmpName,
ED.HomePlace, ED.Qualification
FROM tbl_EmplyeesBiodata ED
ORDER BY DOJInGovrService asc
Date entered is in format dd-MM-yyyy (i.e. 28-08-2004).
please help me
This is just one of many reasons why you should Always use appropriate data types.
Even when you have data in the table, you can change the data type using an alter table ddl statement:
ALTER TABLE tableName
ALTER COLUMN ColumnName datetime2;
However, you should copy this table first and try the alter on the copy, so that if it messes up your data you will not risk anything.
If the alter is successful then do it on your live table. if not, you can go with a different approach, involving these stages:
rename the DOJInGovrService column to DOJInGovrService_old. use sp_RENAME.
Add a column DOJInGovrService with the correct datatype (datetime2), using alter table ddl stement.
Update the new DOJInGovrService column with the values in DOJInGovrService_old. you will probably need to use convert.
drop the DOJInGovrService_old column using the alter table ddl statement.
Try to convert it to datetime
select ED.class,ED.CurrentOfficePlace,ED.DOB,ED.DOJInCurrentOff,ED.DOJInGovrService,ED.DOJInSamvarg,ED.EmpName,ED.HomePlace,ED.Qualification
from tbl_EmplyeesBiodata ED
order by convert(date,DOJInGovrService,105) asc
This is only direct solution. The best way to do that is create new column with date type. The column will helps you to create query without cast or convert.
This question already has answers here:
How to get Oracle create table statement in SQL*Plus
(3 answers)
Closed 7 years ago.
I'm new to sql and I have created table using create table table_name.
And now I want to get this table definition or let's say source code, I know command desc table_name but that's not what I want. Could you help me figure it out?
Check the function: DBMS_METADATA.GET_DDL
http://psoug.org/reference/dbms_metadata.html
This question already has answers here:
How do I UPDATE from a SELECT in SQL Server?
(38 answers)
Closed 8 years ago.
I have a little problem, but I'm sure it s not really complicated.
It's just hard to find the key word to describe the problem and find a solution
I want to update a column in a table using parameters from this table for a query on an other table.
Example : I have Header + 2 lines
IDSOURCE, IDCIBLE, IDENTIFIANT, TABLE_CIBLE, NOM_ATTRIBUT, NOM_CHAMP_IDENTTIFIANT, NOM_CIBLE
--------------------------------------------------------------------------------------------
DMT_1000, DMT_1000, 1000, [dictionnaire].[dbo].[TABLE_CHAMPS_DATAMART], NOM_CHAMP_DMT, IDENTIFIANT_CHAMP_DATAMART, NULL
DMT_1001, DMT_1001, 1001, [dictionnaire].[dbo].[TABLE_CHAMPS_DATAMART], NOM_CHAMP_DMT, IDENTIFIANT_CHAMP_DATAMART, NULL
And I want to update the last column of each line with something like :
UPDATE
Table
SET
Table.NOM_CIBLE = SELECT table.NOM_ATTRIBUT FROM table.TABLE_CIBLE WHERE table.NOM_CHAMP_IDENTTIFIANT = table.IDCIBLE
FROM
Table
Don't know if it s clear.
Thanks for your help.
This sounds like situation where you could use a cursor. Check out this StackOverflow question How to update a column fetched by a cursor