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What is an MDF file? [closed]
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SQL Server databases use two files - an MDF file, known as the primary database file, which contains the schema and data, and a LDF file, which contains the logs. See wikipedia. A database may also use secondary database file...
Oracle find a constraint
...in a table declaration. Or indeed a primary or unique key. For example:
SQL> create table t23 (id number not null primary key)
2 /
Table created.
SQL> select constraint_name, constraint_type
2 from user_constraints
3 where table_name = 'T23'
4 /
CONSTRAINT_NAME ...
How to switch databases in psql?
In MySQL , I used use database_name;
12 Answers
12
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Create SQLite Database and table [closed]
...pplication code, I would like to create and then interact with one or more SQLite databases.
1 Answer
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Handling List-types with Esqueleto
...asking for.
For your case I would insistently advise you to use a classic SQL queries. You can run n+1 queries, but do that only if it is rare and not often usable function, that for example prepares cached data (based on your variables names I suppose that it may not be heavy used and it worth a t...
Is there an SQLite equivalent to MySQL's DESCRIBE [table]?
I'm just getting started learning SQLite . It would be nice to be able to see the details for a table, like MySQL's DESCRIBE [table] . PRAGMA table_info [table] isn't good enough, as it only has basic information (for example, it doesn't show if a column is a field of some sort or not). Does SQL...
How do I find a default constraint using INFORMATION_SCHEMA?
...talog views (sys.*) instead of system table views, which are deprecated in SQL Server 2005 and later.
Below is pretty much the same as @user186476's answer. It returns the name of the default value constraint for a given column. (For non-SQL Server users, you need the name of the default in order t...
How to set a default value for an existing column
This isn't working in SQL Server 2008:
13 Answers
13
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Do htmlspecialchars and mysql_real_escape_string keep my PHP code safe from injection?
...database queries, always try and use prepared parameterised queries. The mysqli and PDO libraries support this. This is infinitely safer than using escaping functions such as mysql_real_escape_string.
Yes, mysql_real_escape_string is effectively just a string escaping function. It is not a magic bu...
SQL multiple column ordering
I am trying to sort by multiple columns in SQL, and in different directions. column1 would be sorted descending, and column2 ascending.
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