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Cannot change column used in a foreign key constraint
I got this error when i was trying to alter my table.
3 Answers
3
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Is SHA-1 secure for password storage?
...ht now even with the "broken" hash functions MD5 and SHA-1.
About rainbow tables:
The "rainbow attack" is actually cost-sharing of a dictionary or brute force attack. It is a derivative from the time-memory trade-off first described by Hellman in 1980. Assuming that you have N possible passwords (...
SQL standard to escape column names?
...ing to SQLite,
'foo' is an SQL string
"foo" is an SQL identifier (column/table/etc)
[foo] is an identifier in MS SQL
`foo` is an identifier in MySQL
For qualified names, the syntax is: "t"."foo" or [t].[foo], etc.
MySQL supports the standard "foo" when the ANSI_QUOTES option is enabled.
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Change cursor to hand when mouse goes over a row in table
...he cursor pointer to hand when my mouse goes over a <tr> in a <table>
11 Answers
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How to do a FULL OUTER JOIN in MySQL?
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For a code SAMPLE transcribed from this SO question you have:
with two tables t1, t2:
SELECT * FROM t1
LEFT JOIN t2 ON t1.id = t2.id
UNION
SELECT * FROM t1
RIGHT JOIN t2 ON t1.id = t2.id
The query above works for special cases where a FULL OUTER JOIN operation would not produce any duplicat...
What is the difference between a schema and a table and a database?
...bably a n00blike (or worse) question. But I've always viewed a schema as a table definition in a database. This is wrong or not entirely correct. I don't remember much from my database courses.
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Script entire database SQL-Server
Is there a way I can get a scripting of all tables, procs, and other objects from a database? I know there's an option to script the database but it only gave me some sort of top level script, certainly not a script to create all tables, procs, udfs, .etc.
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Why do table names in SQL Server start with “dbo”?
At least on my local instance, when I create tables, they are all prefixed with "dbo.". Why is that?
3 Answers
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How to do a batch insert in MySQL
I have 1-many number of records that need to be entered into a table. What is the best way to do this in a query? Should I just make a loop and insert one record per iteration? Or is there a better way?
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In Postgresql, force unique on combination of two columns
I would like to set up a table in PostgreSQL such that two columns together must be unique. There can be multiple values of either value, so long as there are not two that share both.
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