Fixed issues 2546 and 2548

server/config/parameters_list.go

@@ -3556,6 +3556,24 @@ var postgresConfigParameters = map[string]sql.SystemVariable{
 					if err == nil {
 						return v, true
 					}
+					for _, layout := range []string{
+						"-07",
+						"-0700",
+						"-070000",
+						"-07:00",
+						"-07:00:00",
+						"UTC-07",
+						"UTC-0700",
+						"UTC-070000",
+						"UTC-07:00",
+						"UTC-07:00:00",
+						"MST",
+					} {
+						parsed, err := time.Parse(layout, v)
+						if err == nil {
+							return parsed.Format("-07:00:00"), true
+						}
+					}
 					return nil, false
 				}
 			}

server/doltgres_handler.go

@@ -507,7 +507,20 @@ func schemaToFieldDescriptions(ctx *sql.Context, s sql.Schema, formatCodes []int
 		var typmod = int32(-1)
 
 		var err error
+		colName := c.Name
+		dataTypeSize := int16(c.Type.MaxTextResponseByteLength(ctx))
+		tableAttributeNumber := uint16(i + 1) // TODO: this should be based on the actual table field index, not the return schema
 		if doltgresType, ok := c.Type.(*pgtypes.DoltgresType); ok {
+			if doltgresType.ID == pgtypes.Unknown.ID {
+				// It appears that the `unknown` type is always converted to `text` on output since they're binary
+				// coercible. There are other assumptions that we can make as well, as no function or column will return
+				// the `unknown` type, so we can infer that this is a raw value being returned as-is from the query,
+				// such as `SELECT 'foo';`
+				doltgresType = pgtypes.Text
+				dataTypeSize = int16(doltgresType.MaxTextResponseByteLength(ctx))
+				colName = "?column?"
+				tableAttributeNumber = 0
+			}
 			if doltgresType.TypType == pgtypes.TypeType_Domain {
 				oid = id.Cache().ToOID(doltgresType.BaseTypeID.AsId())
 			} else {
@@ -522,11 +535,11 @@ func schemaToFieldDescriptions(ctx *sql.Context, s sql.Schema, formatCodes []int
 		}
 
 		fields[i] = pgproto3.FieldDescription{
-			Name:                 []byte(c.Name),
+			Name:                 []byte(colName),
 			TableOID:             uint32(0),
-			TableAttributeNumber: uint16(i + 1), // TODO: this should be based on the actual table field index, not the return schema
+			TableAttributeNumber: tableAttributeNumber,
 			DataTypeOID:          oid,
-			DataTypeSize:         int16(c.Type.MaxTextResponseByteLength(ctx)),
+			DataTypeSize:         dataTypeSize,
 			TypeModifier:         typmod,
 			Format:               formatCodes[i],
 		}

testing/go/issues_test.go

@@ -407,5 +407,33 @@ limit 1`,
 				},
 			},
 		},
+		{
+			Name: "Issue #2548",
+			SetUpScript: []string{
+				"CREATE TABLE test (pk INT4 PRIMARY KEY, v1 TIMESTAMP WITH TIME ZONE);",
+			},
+			Assertions: []ScriptTestAssertion{
+				{
+					Query:    `SET TimeZone = 'UTC-01:00';`,
+					Expected: []sql.Row{},
+				},
+				{
+					Query:    `INSERT INTO test VALUES (1, '2026-04-15 10:11:12');`,
+					Expected: []sql.Row{},
+				},
+				{
+					Query:    `SET TimeZone = 'UTC-03:00';`,
+					Expected: []sql.Row{},
+				},
+				{
+					Query:    `INSERT INTO test VALUES (2, '2026-04-15 10:11:12');`,
+					Expected: []sql.Row{},
+				},
+				{
+					Query:    `SELECT (SELECT v1 FROM test WHERE pk = 2) - (SELECT v1 FROM test WHERE pk = 1);`,
+					Expected: []sql.Row{{"-02:00:00"}},
+				},
+			},
+		},
 	})
 }

testing/go/wire_test.go

@@ -5186,6 +5186,34 @@ func TestWireTypesSending(t *testing.T) {
 				},
 			},
 		},
+		{ // https://github.com/dolthub/doltgresql/issues/2546
+			Name: "Issue #2546",
+			Assertions: []WireScriptTestAssertion{
+				{
+					Send: []pgproto3.FrontendMessage{
+						&pgproto3.Query{String: "SELECT 'foo';"},
+					},
+					Receive: []pgproto3.BackendMessage{
+						&pgproto3.RowDescription{
+							Fields: []pgproto3.FieldDescription{
+								{
+									Name:                 []byte("?column?"),
+									TableOID:             0,
+									TableAttributeNumber: 0,
+									DataTypeOID:          25,
+									DataTypeSize:         -1,
+									TypeModifier:         -1,
+									Format:               0,
+								},
+							},
+						},
+						&pgproto3.DataRow{Values: [][]byte{[]byte("foo")}},
+						&pgproto3.CommandComplete{CommandTag: []byte("SELECT 1")},
+						&pgproto3.ReadyForQuery{TxStatus: 'I'},
+					},
+				},
+			},
+		},
 	})
 }