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10.3.9 Examples of Character Set and Collation Assignment

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The following examples show how MySQL determines default character set and collation values.

Example 1: Table and Column Definition

  1. CREATE TABLE t1
  2. (
  3.     c1 CHAR(10) CHARACTER SET latin1 COLLATE latin1_german1_ci
  4. ) DEFAULT CHARACTER SET latin2 COLLATE latin2_bin;

Here we have a column with a latin1 character set and a latin1_german1_ci collation. The definition is explicit, so that is straightforward. Notice that there is no problem with storing a latin1 column in a latin2 table.

Example 2: Table and Column Definition

  1. CREATE TABLE t1
  2. (
  3.     c1 CHAR(10) CHARACTER SET latin1
  4. ) DEFAULT CHARACTER SET latin1 COLLATE latin1_danish_ci;

This time we have a column with a latin1 character set and a default collation. Although it might seem natural, the default collation is not taken from the table level. Instead, because the default collation for latin1 is always latin1_swedish_ci, column c1 has a collation of latin1_swedish_ci (not latin1_danish_ci).

Example 3: Table and Column Definition

  1. CREATE TABLE t1
  2. (
  3.     c1 CHAR(10)
  4. ) DEFAULT CHARACTER SET latin1 COLLATE latin1_danish_ci;

We have a column with a default character set and a default collation. In this circumstance, MySQL checks the table level to determine the column character set and collation. Consequently, the character set for column c1 is latin1 and its collation is latin1_danish_ci.

Example 4: Database, Table, and Column Definition

  1. CREATE DATABASE d1
  2.     DEFAULT CHARACTER SET latin2 COLLATE latin2_czech_ci;
  3. USE d1;
  4. CREATE TABLE t1
  5. (
  6.     c1 CHAR(10)
  7. );

We create a column without specifying its character set and collation. We're also not specifying a character set and a collation at the table level. In this circumstance, MySQL checks the database level to determine the table settings, which thereafter become the column settings.) Consequently, the character set for column c1 is latin2 and its collation is latin2_czech_ci.


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Document created the 26/06/2006, last modified the 26/10/2018
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