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Dropping Unique constraint from MySQL table
How can I drop the "Unique Key Constraint" on a column of a MySQL table using phpMyAdmin?
10 Answers
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How to create materialized views in SQL Server?
...ually I want to create a view and it should update automatically when base tables are changed. Can anyone explain with an query example..
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Datatables: Cannot read property 'mData' of undefined
I have an issue with Datatables . I also went through this link which didn't yield any results. I have included all the prerequisites where I'm parsing data directly into the DOM. Kindly help me to fix this issue.
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SQL JOIN - WHERE clause vs. ON clause
...r join has taken place.
b. ON clause - Before joining. Records (from right table) will be filtered before joining. This may end up as null in the result (since OUTER join).
Example: Consider the below tables:
1. documents:
| id | name |
--------|-------------|
| 1 ...
What is cardinality in MySQL?
... of data values contained in a particular column (attribute) of a database table. The lower the cardinality, the more duplicated elements in a column. Thus, a column with the lowest possible cardinality would have the same value for every row. SQL databases use cardinality to help determine the opti...
SQL Server NOLOCK and joins
...argument, just your original question.
Yes, you need WITH(NOLOCK) on each table of the join. No, your queries are not the same.
Try this exercise. Begin a transaction and insert a row into table1 and table2. Don't commit or rollback the transaction yet. At this point your first query will retu...
Is there any significant difference between using if/else and switch-case in C#?
... in debug or compatibility mode. In release, it will be compiled into jump table (through MSIL 'switch' statement)- which is O(1).
C# (unlike many other languages) also allows to switch on string constants - and this works a bit differently. It's obviously not practical to build jump tables for str...
Errors: “INSERT EXEC statement cannot be nested.” and “Cannot use the ROLLBACK statement within an I
...is type of problem.
For example a work around could be to turn Sp3 into a Table-valued function.
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Equivalent of varchar(max) in MySQL?
...are a varchar of the maximum row size, even if it's the only column in the table.
mysql> CREATE TABLE foo ( v VARCHAR(65534) );
ERROR 1118 (42000): Row size too large. The maximum row size for the used table type, not counting BLOBs, is 65535. This includes storage overhead, check the manual. Yo...
How can I temporarily disable a foreign key constraint in MySQL?
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Can I just disable FOREIGN_KEY_CHECKS for a single table?
– jDub9
Dec 20 '18 at 13:53
@Pacerie...