The "ALTER TABLE" is a SQL statement that allows you to make schema changes to a database table (i.e. add, drop or alter columns from an existing table).
Questions tagged [alter-table]
1118 questions
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votes
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Alter column length in SQL
ALTER TABLE tableName
MODIFY COLUMN columnName VARCHAR (256);
Error :
Incorrect syntax near 'VARCHAR'

user3866064
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votes
2 answers
Add calculated column to table ssms (sql query)
Im trying to add and save a new calculated column to the table energy, using the following sql query:
ALTER TABLE energy
ADD energie_active_1 float
SELECT *,
energie_active - LAG(energie_active, 1, energie_active)
…

oussama AY
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1 answer
Set auto_increment for a primary key already created
I created two tables in a database on MariaDB: CasaProduzione and Produzione.
create table CasaProduzione(nome varchar(80) primary key);
alter table CasaProduzione add column id tinyint;
alter table CasaProduzione drop primary key;
alter table…

keiichi
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1 answer
Postgresql issue: help needed
ALTER TABLE populated_places
ALTER COLUMN geom TYPE geography(Point, 4326) USING ST_Transform(geom, 4326)
says:
ERROR: function st_transform(geography, integer) does not exist
LINE 4: geom TYPE geography(Point, 4326) USING ST_Transform(geom,…
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votes
1 answer
Keep getting incorrect syntax near keyword CONSTRAINT in ALTER TABLE when trying to create foreign keys for a table?
I am currently I am working in sql server and have the following code. I am trying to create two foreign keys under the 'ASSIGNMENT' table, as well as create a primary key for the 'ASSIGNMENT' table. However, I keep running into problems when trying…
user18146581
-1
votes
1 answer
Is it safe to add IDENTITY PK Column to existing SQL SERVER table?
After rebuilding all of the tables in one of my SQL SERVER databases, into a new database, I failed to set the 'ID' column to IDENTITY and PRIMARY KEY for many of the tables. Most of them have data.
I discovered this T-SQL, and have successfully…

Jeff King
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votes
2 answers
MySQL Error 1366 when trying to change column data type to INT
I can't figure out why I can't change a column's data type from TEXT to INT. Here is the script I'm using.
ALTER TABLE covidworlddata.coviddeaths
ALTER COLUMN total_deaths INT;
Error 1366: Incorrect integer value: '' for column 'total_deaths' at…

Adam
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votes
3 answers
How to remove unique constraint in MySQL?
I was searching online about how to remove unique constraint in MySQL in the Internet and I found a lot of solutions.
DROP INDEX index_name ON table_name;
ALTER TABLE table_name
DROP INDEX index_name;
ALTER TABLE table_name
DROP CONSTRAINT…

Random Person
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votes
2 answers
What does the FOR keyword do in this SQL Server ALTER TABLE clause?
I'm not sure what FOR is doing in this SQL Server snippet.
ALTER TABLE [dbo].[TableName]
ADD DEFAULT (NEXT VALUE FOR [dbo].[TableName_Seq]) FOR [TableName_Key]
When I try to google for FOR clause the only meaningful result I got was this, but…

Jimmy Vo
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votes
1 answer
Removing a constraint in T-SQL by alter table command - problem
I have got the following code in t-SQL:
alter table Persons
drop primary key;
And the message:
Msg 156, Level 15, State 1, Line 10
Incorrect syntax near the keyword 'primary'.
I have checked different combinations of syntax and none have…

CompactSpaces
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votes
2 answers
Add new column to all tables in database
I'm trying to figure out if there's a quick way or single query to add a new column to all tables in database.
Right now I'm doing this for each table
ALTER TABLE [dbo].[%TABLE_NAME%] ADD %COLUMN_NAME% DATATYPE NOT NULL DEFAULT %VALUE%;
Is there a…

Anthony R
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votes
1 answer
Adding column to table based on whether another column = a specific string
I want to add a column called "Sweep" that contains bools based on whether the "Result" was a sweep or not. So I want the value in the "Sweep" column to be True if the "Result" is '4-0' or '0-4' and False if it isn't.
This is a part of the table:
I…

RKS2
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votes
1 answer
SQL query with ALTER TABLE print error #1064 in query execution
I've built an SQL query in Aruba MySQL database using the alter table Statement to generate a new column with comma-separated values. I'm trying to automate the concatenate function every time a new record is submitted into the database table. After…
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votes
1 answer
Simple SQL question: where is the syntax error?
sqlite> .schema autor
CREATE TABLE autor (ID INTEGER PRIMARY KEY, NOME TEXT, CIDADE TEXT, ESTADO TEXT, TELEFONE TEXT, idade number);
sqlite> alter table autor drop idade;
Error: near "drop": syntax error
(Also tried to use DROP COLUMN instead of…
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votes
2 answers
Varchar to nvarchar without changing length
I have this table that stores an id for each row in sub_id column of type varchar(255), sql server. Other columns store unicode thus those are nvarchar. Now I have this need to update sub_id to nvarchar for SOME reason. I ran following command:
…

pyroCoder
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