implemented sqlite_table_column_metadata

SQLite.xs

@@ -224,8 +224,18 @@ backup_to_file(dbh, filename)
     OUTPUT:
         RETVAL
 
-
+HV*
-
+table_column_metadata(dbh, dbname, tablename, columnname)
+    SV* dbh
+    SV* dbname
+    SV* tablename
+    SV* columnname
+    ALIAS:
+        DBD::SQLite::db::sqlite_table_column_metadata = 1
+    CODE:
+        RETVAL = sqlite_db_table_column_metadata(aTHX_ dbh, dbname, tablename, columnname);
+    OUTPUT:
+        RETVAL
 
 
 static int

dbdimp.c

@@ -1412,6 +1412,43 @@ sqlite_db_enable_load_extension(pTHX_ SV *dbh, int onoff)
 
 #endif
 
+HV* sqlite_db_table_column_metadata(pTHX_ SV *dbh, SV *dbname, SV *tablename, SV *columnname)
+{
+    D_imp_dbh(dbh);
+    const char *datatype, *collseq;
+    int notnull, primary, autoinc;
+    HV *metadata = newHV();
+
+    /* dbname may be NULL but (table|column)name may not be NULL */ 
+    if (!tablename) {
+        sqlite_error(dbh, -2, "table_column_metadata requires a table name");
+        return FALSE;
+    }
+    if (!columnname) {
+        sqlite_error(dbh, -2, "table_column_metadata requires a column name");
+        return FALSE;
+    }
+
+#ifdef SQLITE_ENABLE_COLUMN_METADATA
+    int rc = sqlite3_table_column_metadata(
+       imp_dbh->db,
+       dbname ? SvPV_nolen(dbname) : NULL,
+       SvPV_nolen(tablename),
+       SvPV_nolen(columnname),
+       &datatype, &collseq, &notnull, &primary, &autoinc);
+#endif
+
+    if (rc == SQLITE_OK) {
+        hv_store(metadata, "data_type", 9, newSVpv(datatype, 0), 0);
+        hv_store(metadata, "collation_name", 14, newSVpv(collseq, 0), 0);
+        hv_store(metadata, "not_null", 8, newSViv(notnull), 0);
+        hv_store(metadata, "primary", 7, newSViv(primary), 0);
+        hv_store(metadata, "auto_increment", 14, newSViv(autoinc), 0);
+    }
+
+    return metadata;
+}
+
 static void
 sqlite_db_aggr_new_dispatcher(pTHX_ sqlite3_context *context, aggrInfo *aggr_info)
 {

dbdimp.h

@@ -106,6 +106,7 @@ int sqlite_db_set_authorizer( pTHX_ SV *dbh, SV *authorizer );
 AV* sqlite_compile_options();
 int sqlite_db_trace(pTHX_ SV *dbh, SV *func);
 int sqlite_db_profile(pTHX_ SV *dbh, SV *func);
+HV* sqlite_db_table_column_metadata(pTHX_ SV *dbh, SV *dbname, SV *tablename, SV *columnname);
 
 int sqlite_db_register_fts3_perl_tokenizer(pTHX_ SV *dbh);
 

lib/DBD/SQLite.pm

@@ -51,6 +51,7 @@ sub driver {
         DBD::SQLite::db->install_method('sqlite_register_fts3_perl_tokenizer');
         DBD::SQLite::db->install_method('sqlite_trace');
         DBD::SQLite::db->install_method('sqlite_profile');
+        DBD::SQLite::db->install_method('sqlite_table_column_metadata');
 
         $methods_are_installed++;
     }

t/51_table_column_metadata.t

@@ -0,0 +1,35 @@
+#!/usr/bin/perl
+
+use strict;
+BEGIN {
+	$|  = 1;
+	$^W = 1;
+}
+
+use t::lib::Test qw/connect_ok @CALL_FUNCS/;
+use Test::More;
+use Test::NoWarnings;
+
+plan tests => 11 * @CALL_FUNCS + 1;
+for my $call_func (@CALL_FUNCS) {
+	my $dbh = connect_ok();
+	$dbh->do('create table foo (id integer primary key autoincrement, "name space", unique_col integer unique)');
+
+	{
+		my $data = $dbh->$call_func(undef, 'foo', 'id', 'table_column_metadata');
+		ok $data && ref $data eq ref {}, "got a metadata";
+		ok $data->{auto_increment}, "id is auto incremental";
+		is $data->{data_type} => 'integer', "data type is correct";
+		ok $data->{primary}, "id is a primary key";
+		ok !$data->{not_null}, "id is not null";
+	}
+
+	{
+		my $data = $dbh->$call_func(undef, 'foo', 'name space', 'table_column_metadata');
+		ok $data && ref $data eq ref {}, "got a metadata";
+		ok !$data->{auto_increment}, "name space is not auto incremental";
+		is $data->{data_type} => undef, "data type is not defined";
+		ok !$data->{primary}, "name space is not a primary key";
+		ok !$data->{not_null}, "name space is not null";
+	}
+}