1DBI::DBD::Metadata(3) User Contributed Perl DocumentationDBI::DBD::Metadata(3)
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NAME

6       DBI::DBD::Metadata - Generate the code and data for some DBI metadata
7       methods
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SYNOPSIS

10       The idea is to extract metadata information from a good quality ODBC
11       driver and use it to generate code and data to use in your own DBI
12       driver for the same database.
13
14       To generate code to support the get_info method:
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16         perl -MDBI::DBD::Metadata -e "write_getinfo_pm('dbi:ODBC:dsn-name','user','pass','Driver')"
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18         perl -MDBI::DBD::Metadata -e write_getinfo_pm dbi:ODBC:foo_db username password Driver
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20       To generate code to support the type_info method:
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22         perl -MDBI::DBD::Metadata -e "write_typeinfo_pm('dbi:ODBC:dsn-name','user','pass','Driver')"
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24         perl -MDBI::DBD::Metadata -e write_typeinfo_pm dbi:ODBC:dsn-name user pass Driver
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26       Where "dbi:ODBC:dsn-name" is the connection to use to extract the data,
27       and "Driver" is the name of the driver you want the code generated for
28       (the driver name gets embedded into the output in numerous places).
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Generating a GetInfo package for a driver

31       The "write_getinfo_pm" in the DBI::DBD::Metadata module generates a
32       DBD::Driver::GetInfo package on standard output.
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34       This method generates a DBD::Driver::GetInfo package from the data
35       source you specified in the parameter list or in the environment
36       variable DBI_DSN.  DBD::Driver::GetInfo should help a DBD author
37       implement the DBI get_info() method.  Because you are just creating
38       this package, it is very unlikely that DBD::Driver already provides a
39       good implementation for get_info().  Thus you will probably connect via
40       DBD::ODBC.
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42       Once you are sure that it is producing reasonably sane data, you should
43       typically redirect the standard output to lib/DBD/Driver/GetInfo.pm,
44       and then hand edit the result.  Do not forget to update your
45       Makefile.PL and MANIFEST to include this as an extra PM file that
46       should be installed.
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48       If you connect via DBD::ODBC, you should use version 0.38 or greater;
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50       Please take a critical look at the data returned!  ODBC drivers vary
51       dramatically in their quality.
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53       The generator assumes that most values are static and places these
54       values directly in the %info hash.  A few examples show the use of CODE
55       references and the implementation via subroutines.  It is very likely
56       that you will have to write additional subroutines for values depending
57       on the session state or server version, e.g.  SQL_DBMS_VER.
58
59       A possible implementation of DBD::Driver::db::get_info() may look like:
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61         sub get_info {
62           my($dbh, $info_type) = @_;
63           require DBD::Driver::GetInfo;
64           my $v = $DBD::Driver::GetInfo::info{int($info_type)};
65           $v = $v->($dbh) if ref $v eq 'CODE';
66           return $v;
67         }
68
69       Please replace Driver (or "<foo>") with the name of your driver.  Note
70       that this stub function is generated for you by write_getinfo_pm
71       function, but you must manually transfer the code to Driver.pm.
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Generating a TypeInfo package for a driver

74       The "write_typeinfo_pm" function in the DBI::DBD::Metadata module
75       generates on standard output the data needed for a driver's
76       type_info_all method.  It also provides default implementations of the
77       type_info_all method for inclusion in the driver's main implementation
78       file.
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80       The driver parameter is the name of the driver for which the methods
81       will be generated; for the sake of examples, this will be "Driver".
82       Typically, the dsn parameter will be of the form "dbi:ODBC:odbc_dsn",
83       where the odbc_dsn is a DSN for one of the driver's databases.  The
84       user and pass parameters are the other optional connection parameters
85       that will be provided to the DBI connect method.
86
87       Once you are sure that it is producing reasonably sane data, you should
88       typically redirect the standard output to lib/DBD/Driver/TypeInfo.pm,
89       and then hand edit the result if necessary.  Do not forget to update
90       your Makefile.PL and MANIFEST to include this as an extra PM file that
91       should be installed.
92
93       Please take a critical look at the data returned!  ODBC drivers vary
94       dramatically in their quality.
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96       The generator assumes that all the values are static and places these
97       values directly in the %info hash.
98
99       A possible implementation of DBD::Driver::type_info_all() may look
100       like:
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102         sub type_info_all {
103           my ($dbh) = @_;
104           require DBD::Driver::TypeInfo;
105           return [ @$DBD::Driver::TypeInfo::type_info_all ];
106         }
107
108       Please replace Driver (or "<foo>") with the name of your driver.  Note
109       that this stub function is generated for you by the write_typeinfo_pm
110       function, but you must manually transfer the code to Driver.pm.
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AUTHORS

113       Jonathan Leffler <jleffler@us.ibm.com> (previously
114       <jleffler@informix.com>), Jochen Wiedmann <joe@ispsoft.de>, Steffen
115       Goeldner <sgoeldner@cpan.org>, and Tim Bunce <dbi-users@perl.org>.
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119perl v5.26.3                      2015-05-26             DBI::DBD::Metadata(3)
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