Modify a unique constraint when you want to change the columns that the constraint is attached to, change the constraint name, or set additional properties for the constraint. To modify a unique constraint In your database diagram, right-click the table containing the constraint, then select ...
How to remove duplicate string values in SQL How to remove focus from TextBox in Server-Side (Code Behind) on Button Click event? How to remove HTML control using code behind How to remove marshaling errors for COM-interop or PInvoke how to remove numbers after decimal point How to remove...
If there's an existingnot nullconstraint you want to remove, you can drop it online. To do this you need to find its name. Assuming – like most people – you defined the columnnot nullwithout a specific name, you'll have to look it up first. You can do this by checking the data...
# Step 1: Copy distinct values to temporary table CREATE TEMPORARY TABLE tmp_user ( SELECT id, name FROM user GROUP BY name ); # Step 2: Remove all rows from original table DELETE FROM user; # Step 3: Add Unique constraint ALTER TABLE user ADD UNIQUE(name); # Step 4: Remove all ...
Not sure what you mean here. If a process is blocked by another process, this is seen in sp_who(2), and the blocking spid is there too. If you have a case where a process is said to be blocked by spid 123 and you have no spid with that number, something is really wacko....
I have talbe in sql sever 2005,I want to apply Unique key on Ename field, Primarykey on Eid field Please provide the steps to do this. ThanksReply Answers (1) Its showing error The transaction log for database is full Sql Queries ...
To delete records from a MySQL table, you need to use the DELETE statement in SQL. Here is an example: DELETE FROM table_name WHERE condition; Explanation: "DELETE FROM" is the beginning of the statement that indicates you want to delete records from a table. ...
You can also restore the index file and go back to Stage 2. In the latter case, you should start with myisamchk -r. If you do not have a backup but know exactly how the table was created, create a copy of the table in another database. Remove the new data file, and then ...
If you want to see which is quickest, you canskip straight to the performance comparison. How to Delete Rows with SQL Removing rows is easy. Use adeletestatement. This lists the table you want to remove rows from. Make sure you add awhereclause that identifies the data to wipe, or you...
Database design best practices recommend using the UNIQUE constraint to prevent duplicates in a database. However, when working with a poorly designed database or unclean data, you may need to find duplicates yourself and delete them manually. Read on to learn how to find duplicates in an SQL...