The only other option is to do manually what many RDBMS systems do anyway… – Create a new table You can then copy the contents of the old table over a chunk at a time. Whilst always being cautious of any INSERT/UPDATE/DELETE on the source table. (Could be managed by a trigger. Although this would … Read more
Do you mean altering the table after it has been created? If so you need to use alter table, in particular: ALTER TABLE tablename MODIFY COLUMN new-column-definition e.g. ALTER TABLE test MODIFY COLUMN locationExpect VARCHAR(120);
ALTER TABLE `table_name` MODIFY COLUMN `column_name2` enum( ‘existing_value1’, ‘existing_value2’, ‘new_value1’, ‘new_value2’ ) NOT NULL AFTER `column_name1`;
This is by design. The manual explains in the chapter Variable Substitution: Variable substitution currently works only in SELECT, INSERT, UPDATE, and DELETE commands, because the main SQL engine allows query parameters only in these commands. To use a non-constant name or value in other statement types (generically called utility statements), you must construct the … Read more
The first record will be kept, the rest deleted ยงยง: IGNORE is a MySQL extension to standard SQL. It controls how ALTER TABLE works if there are duplicates on unique keys in the new table or if warnings occur when strict mode is enabled. If IGNORE is not specified, the copy is aborted and rolled … Read more
try: ALTER TABLE `user` CHANGE `id` `id` INT( 11 ) COMMENT ‘id of user’
[2017] Update: MySQL 5.6 has support for online index updates https://dev.mysql.com/doc/refman/8.0/en/innodb-online-ddl-operations.html#online-ddl-index-syntax-notes In MySQL 5.6 and higher, the table remains available for read and write operations while the index is being created or dropped. The CREATE INDEX or DROP INDEX statement only finishes after all transactions that are accessing the table are completed, so that the … Read more
No, you have to add them one at a time. See the syntax diagram at the top of SQLite’s ALTER TABLE documentation: There’s no loop in the ADD branch so no repetition is allowed.
ALTER TABLE TableName ALTER COLUMN ColumnName NVARCHAR(200) [NULL | NOT NULL] EDIT As noted NULL/NOT NULL should have been specified, see Rob’s answer as well.
I cannot reproduce the error. Perhaps I’m not understanding the problem. The following works fine for me in SQL Server 2005, with the extra “foo” column appearing in the second select result: IF OBJECT_ID(‘tempdb..#Results’) IS NOT NULL DROP TABLE #Results GO CREATE TABLE #Results ( Company CHAR(3), StepId TINYINT, FieldId TINYINT ) GO select company, … Read more