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I have 3 columns (_id, column1, column2) _id column has been set as autoincrement
In database there are some duplicate records, so I want to prevent duplicate records with setting column1 as unique indexer. How do I set a column as unique indexer on sqlite? Or how do I prevent duplicate records?
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Introduction to SQLite UNIQUE constraint To define a UNIQUE constraint, you use the UNIQUE keyword followed by one or more columns. You can define a UNIQUE constraint at the column or the table level. Only at the table level, you can define a UNIQUE constraint across multiple columns.
1. Syntax. The CREATE INDEX command consists of the keywords "CREATE INDEX" followed by the name of the new index, the keyword "ON", the name of a previously created table that is to be indexed, and a parenthesized list of table column names and/or expressions that are used for the index key.
Yes, they are the same. A unique constraint in a table definition is exactly and precisely the same as an explicit unique index, save for what is different: an explicit UNIQUE index may contain expressions, a UNIQUE constraint in a table may only contain bare columns.
No magic, just SQL:
create table yourtablename (_id integer primary key autoincrement, column1 text not null unique, column2 text); _id will not be duplicate in any way because it is primary key, column1 neither because it is unique.
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