Fix/custom types

CHANGELOG.md

@@ -23,6 +23,8 @@ v5.0 tracks the NSchema.Core 5.0 rearchitecture. The provider's behaviour is unc
 - Identifiers everywhere in generated SQL are quoted per the core's case-sensitive identifier model; this now includes role names and trigger function references.
 - Revoking table privileges now revokes the specific privileges the plan names rather than `ALL PRIVILEGES`.
 - `ON DELETE NO ACTION` / `ON UPDATE NO ACTION` are no longer spelled out on added foreign keys (they are the engine default).
+- Schema-qualified user-defined type names are now quoted in generated SQL: a column typed as, say, `app.order_status` renders as `"app"."order_status"` rather than bare (an unqualified type name is still emitted as-is).
+- A user-defined type (enum, composite, …) in a non-default schema is now read back schema-qualified during introspection instead of losing its schema, so it no longer produces a spurious diff against a schema-qualified declaration. A type in `public` still reads back unqualified.
 
 ## [4.3.0] - 2026-07-09
 

src/NSchema.Postgres/Models/ColumnRow.cs

@@ -6,6 +6,7 @@ internal sealed record ColumnRow(
     string ColumnName,
     string DataType,
     string UdtName,
+    string? UdtSchema,
     string? DomainSchema,
     string? DomainName,
     int? MaxLength,

src/NSchema.Postgres/NSchema.Postgres.csproj

@@ -20,7 +20,7 @@
     <EmbedUntrackedSources>true</EmbedUntrackedSources>
     <IncludeSymbols>true</IncludeSymbols>
     <SymbolPackageFormat>snupkg</SymbolPackageFormat>
-    <Version>5.0.0-alpha.2</Version>
+    <Version>5.0.0-alpha.3</Version>
     <AssemblyVersion>$(Version.Split('-')[0])</AssemblyVersion>
     <FileVersion>$(Version.Split('-')[0])</FileVersion>
     <TreatWarningsAsErrors>true</TreatWarningsAsErrors>

src/NSchema.Postgres/Sql/PostgresDatabaseIntrospector.cs

@@ -127,7 +127,8 @@ private static async Task<List<ColumnRow>> QueryColumns(NpgsqlConnection conn, s
                 seq.seqstart   AS identity_start,
                 seq.seqmin     AS identity_min_value,
                 seq.seqincrement AS identity_increment,
-                CASE WHEN c.is_generated = 'ALWAYS' THEN c.generation_expression END AS generation_expression
+                CASE WHEN c.is_generated = 'ALWAYS' THEN c.generation_expression END AS generation_expression,
+                c.udt_schema
             FROM information_schema.columns c
             LEFT JOIN pg_namespace    n  ON n.nspname   = c.table_schema
             LEFT JOIN pg_class        t  ON t.relname   = c.table_name
@@ -158,6 +159,7 @@ AND c.table_schema NOT LIKE 'pg\_temp%' ESCAPE '\'
                 ColumnName: reader.GetString(2),
                 DataType: reader.GetString(3),
                 UdtName: reader.GetString(4),
+                UdtSchema: reader.IsDBNull(17) ? null : reader.GetString(17),
                 DomainSchema: reader.IsDBNull(5) ? null : reader.GetString(5),
                 DomainName: reader.IsDBNull(6) ? null : reader.GetString(6),
                 MaxLength: reader.IsDBNull(7) ? null : reader.GetInt32(7),
@@ -1691,7 +1693,7 @@ private static CompositeType MapCompositeType(CompositeTypeRow row, List<Composi
         var fields = allFields
             .Where(f => f.Schema == row.Schema && f.TypeName == row.Name)
             .OrderBy(f => f.OrdinalPosition)
-            .Select(f => new CompositeField(f.FieldName, MapSqlType(f.DataType, f.UdtName, domainSchema: null, domainName: null, f.MaxLength, f.Precision, f.Scale)))
+            .Select(f => new CompositeField(f.FieldName, MapSqlType(f.DataType, f.UdtName, udtSchema: null, domainSchema: null, domainName: null, f.MaxLength, f.Precision, f.Scale)))
             .ToList();
         return new CompositeType { Name = row.Name, Fields = fields, Comment = row.Comment };
     }
@@ -1704,7 +1706,7 @@ private static DomainType MapDomain(DomainRow row, List<DomainCheckRow> allCheck
         return new DomainType
         {
             Name = row.Name,
-            DataType = MapSqlType(row.DataType, row.UdtName, domainSchema: null, domainName: null, row.MaxLength, row.Precision, row.Scale),
+            DataType = MapSqlType(row.DataType, row.UdtName, udtSchema: null, domainSchema: null, domainName: null, row.MaxLength, row.Precision, row.Scale),
             Default = row.Default,
             NotNull = row.NotNull,
             Checks = [.. checks],
@@ -1784,7 +1786,7 @@ private static (IndexSort Sort, IndexNulls Nulls) DecodeIndexOption(int option)
     private static Column MapColumn(ColumnRow row, Dictionary<(string, string, string), string?> columnComments) => new()
     {
         Name = row.ColumnName,
-        Type = MapSqlType(row.DataType, row.UdtName, row.DomainSchema, row.DomainName, row.MaxLength, row.NumericPrecision, row.NumericScale),
+        Type = MapSqlType(row.DataType, row.UdtName, row.UdtSchema, row.DomainSchema, row.DomainName, row.MaxLength, row.NumericPrecision, row.NumericScale),
         IsNullable = row.IsNullable,
         IsIdentity = row.IsIdentity,
         DefaultExpression = row.DefaultExpression,
@@ -1795,7 +1797,7 @@ private static (IndexSort Sort, IndexNulls Nulls) DecodeIndexOption(int option)
         Comment = columnComments.GetValueOrDefault((row.TableSchema, row.TableName, row.ColumnName)),
     };
 
-    private static SqlType MapSqlType(string dataType, string udtName, string? domainSchema, string? domainName, int? maxLength, int? precision, int? scale)
+    private static SqlType MapSqlType(string dataType, string udtName, string? udtSchema, string? domainSchema, string? domainName, int? maxLength, int? precision, int? scale)
     {
         // For a column declared against a domain, information_schema returns the domain's
         // base type in data_type (e.g. "text"). Preserve the domain name so the schema
@@ -1825,7 +1827,9 @@ private static SqlType MapSqlType(string dataType, string udtName, string? domai
             "timestamp with time zone" => SqlType.DateTimeOffset,
             "uuid" => SqlType.Guid,
             "bytea" => SqlType.VarBinary(),
-            _ => SqlType.Custom(udtName),
+            // A user-defined type (enum, composite, …): preserve its schema so the type round-trips, collapsing
+            // the default schema the same way a domain does.
+            _ => udtSchema is null or "public" ? SqlType.Custom(udtName) : SqlType.Custom(udtSchema, udtName),
         };
     }
 

src/NSchema.Postgres/Sql/PostgresSqlDialect.cs

@@ -56,7 +56,7 @@ private static string BuildIdentityClause(IdentityOptions? options)
 
     // ── Type mapping ──────────────────────────────────────────────────────────
 
-    private static string ToPostgresType(SqlType type) => type.Name.Value switch
+    private string ToPostgresType(SqlType type) => type.Name.Value switch
     {
         "boolean" => "boolean",
         "tinyint" => "smallint",
@@ -75,8 +75,8 @@ private static string BuildIdentityClause(IdentityOptions? options)
         "datetimeoffset" => "timestamptz",
         "guid" => "uuid",
         "binary" or "varbinary" => "bytea",
-        // Any other name is a database-specific or user-defined type (e.g. citext, jsonb, a domain);
-        // emit it verbatim, qualified when the model carries a schema.
-        _ => type.Schema is { } schema ? $"{schema.Value}.{type.Name.Value}" : type.Name.Value,
+        // Any other name is a database-specific or user-defined type (e.g. citext, jsonb, a domain); a
+        // schema-qualified type is quoted (a user-defined type in another schema), an unqualified one emitted bare.
+        _ => type.Schema is { } schema ? $"{Quote(schema)}.{Quote(type.Name)}" : type.Name.Value,
     };
 }

tests/NSchema.Postgres.Tests/Sql/PostgresDatabaseIntrospectorTests.cs

@@ -803,9 +803,10 @@ await Exec($"""
     }
 
     [Fact]
-    public async Task GetDatabase_EnumColumn_MappedAsCustomType()
+    public async Task GetDatabase_EnumColumn_MappedAsCustomType_PreservingSchema()
     {
-        // Arrange — a column typed as a user-defined enum comes back through MapSqlType's fall-through.
+        // Arrange — a column typed as a user-defined enum comes back through MapSqlType's fall-through; its
+        // udt_schema is preserved so a type in another schema round-trips.
         await Exec($"""
             CREATE TYPE "{_schema}".order_status AS ENUM ('draft', 'active');
             CREATE TABLE "{_schema}".orders (status "{_schema}".order_status NOT NULL);
@@ -816,7 +817,7 @@ await Exec($"""
             .Schemas[0].Tables.ShouldHaveSingleItem().Columns.ShouldHaveSingleItem();
 
         // Assert
-        column.Type.ShouldBe(SqlType.Custom("order_status"));
+        column.Type.ShouldBe(SqlType.Custom(_schema, "order_status"));
     }
 
     // ── Sequences ─────────────────────────────────────────────────────────────

tests/NSchema.Postgres.Tests/Sql/Snapshots/PostgresSqlDialectSnapshotTests.TypeMapping_CoversAllSqlTypes.verified.txt

@@ -92,7 +92,7 @@
     RunOutsideTransaction: false
   },
   {
-    Sql: ALTER TABLE "public"."t" ALTER COLUMN "c" TYPE app.order_status,
+    Sql: ALTER TABLE "public"."t" ALTER COLUMN "c" TYPE "app"."order_status",
     RunOutsideTransaction: false
   }
 ]