Quickstart (recommended), which uses the default database (SQLite).Value, see Section 11.6, “Data Type Default Values”. For more informationĪbout default value handling, including the case that a column Storage engines support indexes on columns that can haveĭeclare indexed columns as NOT NULL or an NULL is specified, the column is treated as though Indexing a Generated Column to Provide a JSON Column Index, for a You can work around this restriction by creatingĪn index on a generated column that extracts a scalar
Insertion of nonunique entries that do not meet the Mode because reducing the index length might enable Size and a warning is produced (if strict SQL mode isįor a unique index, an error occurs regardless of SQL Reduced to lie within the maximum column data type Strict SQL mode is enabled), or the index length is If a specified index prefix exceeds the maximum columnįor a nonunique index, either an error occurs (if Prefixes, see Section 13.1.15, “CREATE INDEX Statement”.ĬREATE TABLE test (blob_col BLOB, INDEX(blob_col(10))) That is, index entries consist of the firstĪ prefix of column values like this can make the indexįile much smaller. Nonbinary string types and in bytes for binary string Prefix lengths are given in characters for Syntax to specify an index prefix length. Lengths forĬan be created that use only the leading part of column MySQL 8.0 interprets length specifications inĬharacter column definitions in characters. For details, see Chapter 10, Character Sets, Collations, Unicode.ĬREATE TABLE t (c CHAR(20) CHARACTER SET utf8mb4 COLLATE utf8mb4_bin) Prior to MySQL 8.0.13,Ĭollation for the character set can be specified with theĪttributes. Some attributes do not apply to all data types.Īnd floating-point types. Maximum may be less for a given table and depends on the factorsĭiscussed in Section 8.4.7, “Limits on Table Column Count and Row Size”. There is a hard limit of 4096 columns per table, but the effective
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Options indicate how to handle rows that duplicate unique key LIKE Statement”.ĬREATE TABLE new_tbl AS SELECT * FROM orig_tbl Including any column attributes and indexes defined in theįor more information, see Section 13.1.20.3, “CREATE TABLE. TABLE statement, described under the following topics inĮmpty table based on the definition of another table, Section 13.1.20.1, “Files Created by CREATE TABLE”. InnoDB permits up to 4 billionįor information about the physical representation of a table, see Individual storage engines may impose engine-specificĬonstraints. System may have a limit on the number of files that represent MySQL has no limit on the number of tables. Occurs if the table exists, if there is no default database, or if ( Some valid select or union statement)īy default, tables are created in the default database, using the
SELECT Statement 13.1.20.5 FOREIGN KEY Constraints 13.1.20.6 CHECK Constraints 13.1.20.7 Silent Column Specification Changes 13.1.20.8 CREATE TABLE and Generated Columns 13.1.20.9 Secondary Indexes and Generated Columns 13.1.20.10 Invisible Columns 13.1.20.11 Generated Invisible Primary Keys 13.1.20.12 Setting NDB Comment Options CREATE TABLE tbl_nameĬREATE TABLE tbl_name 13.1.20.1 Files Created by CREATE TABLE 13.1.20.2 CREATE TEMPORARY TABLE Statement 13.1.20.3 CREATE TABLE.
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