alter-table

问题 How can I alter a Mysql table time stamp to such as the following: dd/mm/yy 00:00:00 I tried: ALTER TABLE TbMessage MODIFY startdate TIMESTAMP DEFAULT CURRENT_TIMESTAMP NOT NULL; But is not the formate as i thought: 0000-00-00 00:00:00 can some one help me? Because the date which i am receiving for the table is in the format DD/MM/YYYY from a SQL Database. I cant chnage the formate in the database of SQL. 回答1: A timestamp / datetime is always stored the same way in the database. It is the

问题 I'm trying to convert the column, and preserve the data in the specified timezone. I have a script, but it errors out on the SELECT at the end. ALTER TABLE schema.table ALTER COLUMN column_date TYPE TIMESTAMP WITH TIME ZONE USING column_date AT TIME ZONE (SELECT value FROM schema.table WHERE id = 'timezone'); ERROR: cannot use subquery in transform expression I have time zones stored, but trying to pull that back to apply to the script is posing a challenge. I know I can simply hardcode the

问题 I'm trying to convert the column, and preserve the data in the specified timezone. I have a script, but it errors out on the SELECT at the end. ALTER TABLE schema.table ALTER COLUMN column_date TYPE TIMESTAMP WITH TIME ZONE USING column_date AT TIME ZONE (SELECT value FROM schema.table WHERE id = 'timezone'); ERROR: cannot use subquery in transform expression I have time zones stored, but trying to pull that back to apply to the script is posing a challenge. I know I can simply hardcode the

问题 I have an attribute in a table like this: created_date timestamp without timezone Now my requirement is to change the created_date field to the timestamp with timezone on the production database but I don't know how to alter this constraint. 回答1: To change a column type use ALTER TABLE command: ALTER TABLE yourtable ALTER COLUMN column_name TYPE timestamptz; You can change more than 1 column type in one operation by delimiting ALTER COLUMN statements with a comma: ALTER TABLE yourtable ALTER

问题 Teradata has the concept of lastaltertimestamp , which is the last time an alter table command was executed on a table. lastaltertimestamp can be queried. Does Hive have a similar value that can be queried? The timestamp returned by hdfs dfs -ls /my/hive/file does not reflect alter table commands, so alter table must not modify the file backing Hive file. describe formatted does not provide a last-alter-timestamp either. Thanks 回答1: Hive stores metadata into a database, so files never get

来源： https://stackoverflow.com/questions/6324414/alter-domain-change-type

来源： https://stackoverflow.com/questions/6324414/alter-domain-change-type

问题 I can't find what the syntax looks like for adding a DATETIME column to a mysql table when I want to set the default to - example - 2011-01-26 14:30:00 Does anyone know what that syntax looks like? Here's what I've got ADD COLUMN new_date DATETIME AFTER preceding_col, Thanks 回答1: If you ever have doubts, the syntax is explained here http://dev.mysql.com/doc/refman/5.5/en/alter-table.html ALTER TABLE yourTable ADD COLUMN new_date DATETIME NOT NULL DEFAULT 20110126143000 AFTER preceding_col or

问题 I have one problem with the ALTER TABLE in postgre. I want to change size of the varchar column. When I try to do this, It says that the view is dependent on that column. I can't drop the view because comething else is dependent on it. Is there any other way than to drop everything and recreate it again? I just found one option, which is to remove the table joining from the view, when I will not change the returned columns, I can do that. But still, there is more views I'll need to change.

问题 I have one problem with the ALTER TABLE in postgre. I want to change size of the varchar column. When I try to do this, It says that the view is dependent on that column. I can't drop the view because comething else is dependent on it. Is there any other way than to drop everything and recreate it again? I just found one option, which is to remove the table joining from the view, when I will not change the returned columns, I can do that. But still, there is more views I'll need to change.