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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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How to change collation of database, table, column?
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You need to either convert each table individually:
ALTER TABLE mytable CONVERT TO CHARACTER SET utf8mb4
(this will convert the columns just as well), or export the database with latin1 and import it back with utf8mb4.
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How are virtual functions and vtable implemented?
...ons in C++":
Whenever a program has a virtual function declared, a v - table is constructed for the class. The v-table consists of addresses to the virtual functions for classes that contain one or more virtual functions. The object of the class containing the virtual function contains a virtual...
Java HashMap performance optimization / alternative
...h code as mmyers and rsp suggest is better. In my case my solution is acceptable and I wanted to highlight the fact that the arrays must be sorted for hashCode() to work.
– nash
Nov 19 '09 at 17:00
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Using an RDBMS as event sourcing storage
...1 and 2 at all.
Below is the schema as used in Ncqrs. As you can see, the table "Events" stores the related data as a CLOB (i.e. JSON or XML). This corresponds to your option 3 (Only that there is no "ProductEvents" table because you only need one generic "Events" table. In Ncqrs the mapping to you...
SQL MAX of multiple columns?
...(VALUES (date1), (date2), (date3),...) AS value(v)) as [MaxDate]
FROM [YourTableName]
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Combining INSERT INTO and WITH/CTE
...e a very complex CTE and I would like to insert the result into a physical table.
3 Answers
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Align DIV's to bottom or baseline
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Use the CSS display values of table and table-cell:
HTML
<html>
<body>
<div class="valign bottom">
<div>
<div>my bottom aligned div 1</div>
<div>my bottom aligned div 2</div>
<...
Safely remove migration In Laravel
...p-autoload
Modify your database: Remove the last entry from the migrations table
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SQL Server insert if not exists best practice
I have a Competitions results table which holds team member's names and their ranking on one hand.
8 Answers
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