alter-table

I have a production database where I have renamed several column's that are foreign keys. Obviously mysql makes this a real pain to do in my experience. My solution was to drop all the indexes and foreign keys, rename the id columns, and then re-add the indexes and foreign keys. This works great on mysql 5.1 on windows for the development database. I went to run my migration script on my debian server, which is also using mysql 5.1, and it gives the following error: mysql> ALTER TABLE `company_to_module` -> ADD CONSTRAINT `FK82977604FE40A062` FOREIGN KEY (`company_id`) REFERENCES `company` (

For example: ALTER TABLE webstore.Store MODIFY COLUMN ( ShortName VARCHAR(100), UrlShort VARCHAR(100) ); The above however does not work. I am using MySql 5.x ALTER TABLE can do multiple table alterations in one statement, but MODIFY COLUMN can only work on one column at a time, so you need to specify MODIFY COLUMN for each column you want to change: ALTER TABLE webstore.Store MODIFY COLUMN ShortName VARCHAR(100), MODIFY COLUMN UrlShort VARCHAR(100); Also, note this warning from the manual: When you use CHANGE or MODIFY, column_definition must include the data type and all attributes that

I've tried the following, but I was unsuccessful: ALTER TABLE person ALTER COLUMN dob POSITION 37; " Alter column position " in the PostgreSQL Wiki says: PostgreSQL currently defines column order based on the attnum column of the pg_attribute table. The only way to change column order is either by recreating the table, or by adding columns and rotating data until you reach the desired layout. That's pretty weak, but in their defense, in standard SQL, there is no solution for repositioning a column either. Database brands that support changing the ordinal position of a column are defining an

The MySQL reference manual does not provide a clearcut example on how to do this. I have an ENUM-type column of country names that I need to add more countries to. What is the correct MySQL syntax to achieve this? Here's my attempt: ALTER TABLE carmake CHANGE country country ENUM('Sweden','Malaysia'); The error I get is: ERROR 1265 (01000): Data truncated for column 'country' at row 1. The country column is the ENUM-type column in the above-statement. SHOW CREATE TABLE OUTPUT: mysql> SHOW CREATE TABLE carmake; +---------+---------------------------------------------------------------------+ |

I'm adding a new, "NOT NULL" column to my Postgresql database using the following query (sanitized for the Internet): ALTER TABLE mytable ADD COLUMN mycolumn character varying(50) NOT NULL; Each time I run this query, I receive the following error message: ERROR: column "mycolumn" contains null values I'm stumped. Where am I going wrong? NOTE: I'm using pgAdmin III (1.8.4) primarily, but I received the same error when I ran the SQL from within Terminal. You have to set a default value. ALTER TABLE mytable ADD COLUMN mycolumn character varying(50) NOT NULL DEFAULT 'foo'; ... some work (set real

If i want to use a variable as name of the new column, is this posible in MS SQL? Example that dont work: ALTER TABLE my_table ADD @column INT This worked great for me: EXEC ('ALTER TABLE my_table ADD ' + @column + ' INT') This is possible using dynamic sql to build your DDL and using the EXEC command to execute the string. Declare @SQL VarChar(1000) SELECT @SQL = 'ALTER TABLE my_table ADD ' + @column + ' INT' Exec (@SQL) See this article. I will also add that the moment you venture to the land of dynamic sql, you need to take care to not expose yourself to SQL Injection attacks . Always clean

I want to add a column to a table, but I don't want it to fail if it has already been added to the table. How can I achieve this? # Add column fails if it already exists ALTER TABLE `TableName` ADD `ColumnName` int(1) NOT NULL default '0'; Use the following in a stored procedure: IF NOT EXISTS( SELECT NULL FROM INFORMATION_SCHEMA.COLUMNS WHERE table_name = 'tablename' AND table_schema = 'db_name' AND column_name = 'columnname') THEN ALTER TABLE `TableName` ADD `ColumnName` int(1) NOT NULL default '0'; END IF; Reference: The INFORMATION_SCHEMA COLUMNS Table 来源： https://stackoverflow.com