Add domain support

fixes #407

CHANGELOG.md

@@ -4,6 +4,7 @@
 
 * Support sslkey, sslcert, and sslrootcert URI params (Sean Chittenden)
 * Allow any scheme in ParseURI (for convenience with cockroachdb) (Sean Chittenden)
+* Add support for domain types
 
 ## Fixes
 

README.md

@@ -100,6 +100,7 @@ Then run the following SQL:
 Connect to database pgx_test and run:
 
     create extension hstore;
+    create domain uint64 as numeric(20,0);
 
 Next open conn_config_test.go.example and make a copy without the
 .example. If your PostgreSQL server is accepting connections on 127.0.0.1,

conn.go

@@ -15,6 +15,7 @@ import (
 	"os"
 	"os/user"
 	"path/filepath"
+	"reflect"
 	"regexp"
 	"strconv"
 	"strings"
@@ -428,6 +429,10 @@ where (
 		return nil, err
 	}
 
+	if err = c.initConnInfoDomains(cinfo); err != nil {
+		return nil, err
+	}
+
 	return cinfo, nil
 }
 
@@ -494,6 +499,52 @@ where t.typtype = 'b'
 	return nil
 }
 
+// initConnInfoDomains introspects for domains and registers a data type for them.
+func (c *Conn) initConnInfoDomains(cinfo *pgtype.ConnInfo) error {
+	type domain struct {
+		oid     pgtype.OID
+		name    string
+		baseOID pgtype.OID
+	}
+
+	domains := make([]*domain, 0, 16)
+
+	rows, err := c.Query(`select t.oid, t.typname, t.typbasetype
+from pg_type t
+  join pg_type base_type on t.typbasetype=base_type.oid
+where t.typtype = 'd'
+  and base_type.typtype = 'b'`)
+	if err != nil {
+		return err
+	}
+
+	for rows.Next() {
+		var d domain
+		if err := rows.Scan(&d.oid, &d.name, &d.baseOID); err != nil {
+			return err
+		}
+
+		domains = append(domains, &d)
+	}
+
+	if rows.Err() != nil {
+		return rows.Err()
+	}
+
+	for _, d := range domains {
+		baseDataType, ok := cinfo.DataTypeForOID(d.baseOID)
+		if ok {
+			cinfo.RegisterDataType(pgtype.DataType{
+				Value: reflect.New(reflect.ValueOf(baseDataType.Value).Elem().Type()).Interface().(pgtype.Value),
+				Name:  d.name,
+				OID:   d.oid,
+			})
+		}
+	}
+
+	return nil
+}
+
 // crateDBTypesQuery checks if the given err is likely to be the result of
 // CrateDB not implementing the pg_types table correctly. If yes, a CrateDB
 // specific query against pg_types is executed and its results are returned. If

conn_test.go

@@ -2073,3 +2073,28 @@ func TestConnInitConnInfo(t *testing.T) {
 
 	ensureConnValid(t, conn)
 }
+
+func TestDomainType(t *testing.T) {
+	conn := mustConnect(t, *defaultConnConfig)
+	defer closeConn(t, conn)
+
+	dt, ok := conn.ConnInfo.DataTypeForName("uint64")
+	if !ok {
+		t.Fatal("Expected data type for domain uint64 to be present")
+	}
+	if dt, ok := dt.Value.(*pgtype.Numeric); !ok {
+		t.Fatal("Expected data type value for domain uint64 to be *pgtype.Numeric, but it was %T", dt)
+	}
+
+	var n uint64
+	err := conn.QueryRow("select $1::uint64", uint64(42)).Scan(&n)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if n != 42 {
+		t.Fatalf("Expected n to be 42, but was %v", n)
+	}
+
+	ensureConnValid(t, conn)
+}

pgmock/pgmock.go

@@ -479,6 +479,55 @@ where (
 		SendMessage(&pgproto3.ReadyForQuery{TxStatus: 'I'}),
 	}...)
 
+	steps = append(steps, []Step{
+		ExpectMessage(&pgproto3.Parse{
+			Query: "select t.oid, t.typname, t.typbasetype\nfrom pg_type t\n  join pg_type base_type on t.typbasetype=base_type.oid\nwhere t.typtype = 'd'\n  and base_type.typtype = 'b'",
+		}),
+		ExpectMessage(&pgproto3.Describe{
+			ObjectType: 'S',
+		}),
+		ExpectMessage(&pgproto3.Sync{}),
+		SendMessage(&pgproto3.ParseComplete{}),
+		SendMessage(&pgproto3.ParameterDescription{}),
+		SendMessage(&pgproto3.RowDescription{
+			Fields: []pgproto3.FieldDescription{
+				{Name: "oid",
+					TableOID:             1247,
+					TableAttributeNumber: 65534,
+					DataTypeOID:          26,
+					DataTypeSize:         4,
+					TypeModifier:         4294967295,
+					Format:               0,
+				},
+				{Name: "typname",
+					TableOID:             1247,
+					TableAttributeNumber: 1,
+					DataTypeOID:          19,
+					DataTypeSize:         64,
+					TypeModifier:         4294967295,
+					Format:               0,
+				},
+				{Name: "typbasetype",
+					TableOID:             1247,
+					TableAttributeNumber: 65534,
+					DataTypeOID:          26,
+					DataTypeSize:         4,
+					TypeModifier:         4294967295,
+					Format:               0,
+				},
+			},
+		}),
+		SendMessage(&pgproto3.ReadyForQuery{TxStatus: 'I'}),
+		ExpectMessage(&pgproto3.Bind{
+			ResultFormatCodes: []int16{1, 1, 1},
+		}),
+		ExpectMessage(&pgproto3.Execute{}),
+		ExpectMessage(&pgproto3.Sync{}),
+		SendMessage(&pgproto3.BindComplete{}),
+		SendMessage(&pgproto3.CommandComplete{CommandTag: "SELECT 0"}),
+		SendMessage(&pgproto3.ReadyForQuery{TxStatus: 'I'}),
+	}...)
+
 	return steps
 }
 

travis/before_script.bash

@@ -9,6 +9,7 @@ then
   # of aclitem formatting. It turns out aclitems cannot contain non-existing users/roles.
   psql -U postgres -c 'create database pgx_test'
   psql -U postgres pgx_test -c 'create extension hstore'
+  psql -U postgres pgx_test -c 'create domain uint64 as numeric(20,0)'
   psql -U postgres -c "create user pgx_ssl SUPERUSER PASSWORD 'secret'"
   psql -U postgres -c "create user pgx_md5 SUPERUSER PASSWORD 'secret'"
   psql -U postgres -c "create user pgx_pw  SUPERUSER PASSWORD 'secret'"