NAME

DBIx::Util::Schema - Utility routines related to database schema

VERSION

This document describes version 0.002 of DBIx::Util::Schema (from Perl distribution DBIx-Util-Schema), released on 2020-05-06.

SYNOPSIS

 use DBIx::Util::Schema qw(
     table_exists
     column_exists

     list_tables
     list_columns
     list_indexes
 );

 say "Database has table named 'foo'" if table_exists($dbh, "foo");

DESCRIPTION

DBI already provides methods to query schema information, e.g. table_info(), column_info(), statistics_info(), but simple things like checking whether a table or a column exists is not straightforward or easy enough. This module provides convenience routines for those tasks.

Currently only tested on SQLite, MySQL, and Postgres.

FUNCTIONS

column_exists

Usage:

 column_exists($dbh, $table, $column) -> any

Alias for has_column().

This function is not exported by default, but exportable.

Arguments ('*' denotes required arguments):

• $column* => str

  Table column name.

• $dbh* => obj

  DBI database handle.

• $table* => str

  Table name.

Return value: (any)

has_all_columns

Usage:

 has_all_columns($dbh, $table, $columns, ...) -> any

Check whether a table has all specified columns.

This function is not exported by default, but exportable.

Arguments ('*' denotes required arguments):

• $columns* => array[str]

  Table column names.

• $dbh* => obj

  DBI database handle.

• $table* => str

  Table name.

Return value: (any)

has_all_tables

Usage:

 has_all_tables($dbh, $tables, ...) -> any

Check whether database has all specified tables.

This function is not exported by default, but exportable.

Arguments ('*' denotes required arguments):

• $dbh* => obj

  DBI database handle.

• $tables* => array[str]

  Table names.

Return value: (any)

has_any_column

Usage:

 has_any_column($dbh, $table, $columns, ...) -> any

Check whether a table has at least one of specified columns.

This function is not exported by default, but exportable.

Arguments ('*' denotes required arguments):

• $columns* => array[str]

  Table column names.

• $dbh* => obj

  DBI database handle.

• $table* => str

  Table name.

Return value: (any)

has_any_table

Usage:

 has_any_table($dbh, $tables, ...) -> any

Check whether database has at least one of specified tables.

This function is not exported by default, but exportable.

Arguments ('*' denotes required arguments):

• $dbh* => obj

  DBI database handle.

• $tables* => array[str]

  Table names.

Return value: (any)

has_column

Usage:

 has_column($dbh, $table, $column) -> any

Check whether a table has a specified column.

This function is not exported by default, but exportable.

Arguments ('*' denotes required arguments):

• $column* => str

  Table column name.

• $dbh* => obj

  DBI database handle.

• $table* => str

  Table name.

Return value: (any)

has_table

Usage:

 has_table($dbh, $table) -> any

Check whether database has a certain table.

This function is not exported by default, but exportable.

Arguments ('*' denotes required arguments):

• $dbh* => obj

  DBI database handle.

• $table* => str

  Table name.

Return value: (any)

list_columns

Usage:

 list_columns($dbh, $table) -> any

List columns of a table.

This function is not exported by default, but exportable.

Arguments ('*' denotes required arguments):

• $dbh* => obj

  DBI database handle.

• $table* => str

  Table name.

Return value: (any)

list_indexes

Usage:

 list_indexes($dbh, $table) -> any

List indexes for a table in a database.

SQLite notes: information is retrieved from DBI's table_info(). Autoindex for primary key is not listed using table_info(), but this function adds it by looking at sqlite_master table.

MySQL notes: information is retrieved from statistics_info(). Note that a multi-column index is reported as separate rows by statistics_info(), one for each indexed column. But this function merges them and returns the list of columns in columns.

This function is not exported by default, but exportable.

Arguments ('*' denotes required arguments):

• $dbh* => obj

  DBI database handle.

• $table* => str

  Table name.

Return value: (any)

list_tables

Usage:

 list_tables($dbh) -> any

List table names in a database.

This function is not exported by default, but exportable.

Arguments ('*' denotes required arguments):

• $dbh* => obj

  DBI database handle.

Return value: (any)

table_exists

Usage:

 table_exists($dbh, $table) -> any

Alias for has_table().

This function is not exported by default, but exportable.

Arguments ('*' denotes required arguments):

• $dbh* => obj

  DBI database handle.

• $table* => str

  Table name.

Return value: (any)

HOMEPAGE

Please visit the project's homepage at https://metacpan.org/release/DBIx-Util-Schema.

SOURCE

Source repository is at https://github.com/perlancar/perl-DBIx-Util-Schema.

BUGS

Please report any bugs or feature requests on the bugtracker website https://rt.cpan.org/Public/Dist/Display.html?Name=DBIx-Util-Schema

When submitting a bug or request, please include a test-file or a patch to an existing test-file that illustrates the bug or desired feature.

SEE ALSO

Test::DBUnit currently has more methods.

DBI

AUTHOR

perlancar <perlancar@cpan.org>

COPYRIGHT AND LICENSE

This software is copyright (c) 2020 by perlancar@cpan.org.

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.

cpanm DBIx::Util::Schema

perl -MCPAN -e shell
install DBIx::Util::Schema