Add ColumnType support

conn.go

@@ -706,7 +706,7 @@ func (noRows) RowsAffected() (int64, error) {
 
 // Decides which column formats to use for a prepared statement.  The input is
 // an array of type oids, one element per result column.
-func decideColumnFormats(colTyps []oid.Oid, forceText bool) (colFmts []format, colFmtData []byte) {
+func decideColumnFormats(colTyps []fieldDesc, forceText bool) (colFmts []format, colFmtData []byte) {
 	if len(colTyps) == 0 {
 		return nil, colFmtDataAllText
 	}
@@ -718,8 +718,8 @@ func decideColumnFormats(colTyps []oid.Oid, forceText bool) (colFmts []format, c
 
 	allBinary := true
 	allText := true
-	for i, o := range colTyps {
-		switch o {
+	for i, t := range colTyps {
+		switch t.OID {
 		// This is the list of types to use binary mode for when receiving them
 		// through a prepared statement.  If a type appears in this list, it
 		// must also be implemented in binaryDecode in encode.go.
@@ -1155,7 +1155,7 @@ type stmt struct {
 	colNames   []string
 	colFmts    []format
 	colFmtData []byte
-	colTyps    []oid.Oid
+	colTyps    []fieldDesc
 	paramTyps  []oid.Oid
 	closed     bool
 }
@@ -1318,7 +1318,7 @@ type rows struct {
 	cn       *conn
 	finish   func()
 	colNames []string
-	colTyps  []oid.Oid
+	colTyps  []fieldDesc
 	colFmts  []format
 	done     bool
 	rb       readBuf
@@ -1406,7 +1406,7 @@ func (rs *rows) Next(dest []driver.Value) (err error) {
 					dest[i] = nil
 					continue
 				}
-				dest[i] = decode(&conn.parameterStatus, rs.rb.next(l), rs.colTyps[i], rs.colFmts[i])
+				dest[i] = decode(&conn.parameterStatus, rs.rb.next(l), rs.colTyps[i].OID, rs.colFmts[i])
 			}
 			return
 		case 'T':
@@ -1573,7 +1573,7 @@ func (cn *conn) readParseResponse() {
 	}
 }
 
-func (cn *conn) readStatementDescribeResponse() (paramTyps []oid.Oid, colNames []string, colTyps []oid.Oid) {
+func (cn *conn) readStatementDescribeResponse() (paramTyps []oid.Oid, colNames []string, colTyps []fieldDesc) {
 	for {
 		t, r := cn.recv1()
 		switch t {
@@ -1599,7 +1599,7 @@ func (cn *conn) readStatementDescribeResponse() (paramTyps []oid.Oid, colNames [
 	}
 }
 
-func (cn *conn) readPortalDescribeResponse() (colNames []string, colFmts []format, colTyps []oid.Oid) {
+func (cn *conn) readPortalDescribeResponse() (colNames []string, colFmts []format, colTyps []fieldDesc) {
 	t, r := cn.recv1()
 	switch t {
 	case 'T':
@@ -1695,31 +1695,33 @@ func (cn *conn) readExecuteResponse(protocolState string) (res driver.Result, co
 	}
 }
 
-func parseStatementRowDescribe(r *readBuf) (colNames []string, colTyps []oid.Oid) {
+func parseStatementRowDescribe(r *readBuf) (colNames []string, colTyps []fieldDesc) {
 	n := r.int16()
 	colNames = make([]string, n)
-	colTyps = make([]oid.Oid, n)
+	colTyps = make([]fieldDesc, n)
 	for i := range colNames {
 		colNames[i] = r.string()
 		r.next(6)
-		colTyps[i] = r.oid()
-		r.next(6)
+		colTyps[i].OID = r.oid()
+		colTyps[i].Len = r.int16()
+		colTyps[i].Mod = r.int32()
 		// format code not known when describing a statement; always 0
 		r.next(2)
 	}
 	return
 }
 
-func parsePortalRowDescribe(r *readBuf) (colNames []string, colFmts []format, colTyps []oid.Oid) {
+func parsePortalRowDescribe(r *readBuf) (colNames []string, colFmts []format, colTyps []fieldDesc) {
 	n := r.int16()
 	colNames = make([]string, n)
 	colFmts = make([]format, n)
-	colTyps = make([]oid.Oid, n)
+	colTyps = make([]fieldDesc, n)
 	for i := range colNames {
 		colNames[i] = r.string()
 		r.next(6)
-		colTyps[i] = r.oid()
-		r.next(6)
+		colTyps[i].OID = r.oid()
+		colTyps[i].Len = r.int16()
+		colTyps[i].Mod = r.int32()
 		colFmts[i] = format(r.int16())
 	}
 	return

oid/gen.go

@@ -10,10 +10,22 @@ import (
 	"log"
 	"os"
 	"os/exec"
+	"strings"
 
 	_ "github.com/lib/pq"
 )
 
+// OID represent a postgres Object Identifier Type.
+type OID struct {
+	ID   int
+	Type string
+}
+
+// Name returns an upper case version of the oid type.
+func (o OID) Name() string {
+	return strings.ToUpper(o.Type)
+}
+
 func main() {
 	datname := os.Getenv("PGDATABASE")
 	sslmode := os.Getenv("PGSSLMODE")
@@ -30,6 +42,25 @@ func main() {
 	if err != nil {
 		log.Fatal(err)
 	}
+	rows, err := db.Query(`
+		SELECT typname, oid
+		FROM pg_type WHERE oid < 10000
+		ORDER BY oid;
+	`)
+	if err != nil {
+		log.Fatal(err)
+	}
+	oids := make([]*OID, 0)
+	for rows.Next() {
+		var oid OID
+		if err = rows.Scan(&oid.Type, &oid.ID); err != nil {
+			log.Fatal(err)
+		}
+		oids = append(oids, &oid)
+	}
+	if err = rows.Err(); err != nil {
+		log.Fatal(err)
+	}
 	cmd := exec.Command("gofmt")
 	cmd.Stderr = os.Stderr
 	w, err := cmd.StdinPipe()
@@ -45,30 +76,18 @@ func main() {
 	if err != nil {
 		log.Fatal(err)
 	}
-	fmt.Fprintln(w, "// generated by 'go run gen.go'; do not edit")
+	fmt.Fprintln(w, "// Code generated by gen.go. DO NOT EDIT.")
 	fmt.Fprintln(w, "\npackage oid")
 	fmt.Fprintln(w, "const (")
-	rows, err := db.Query(`
-		SELECT typname, oid
-		FROM pg_type WHERE oid < 10000
-		ORDER BY oid;
-	`)
-	if err != nil {
-		log.Fatal(err)
-	}
-	var name string
-	var oid int
-	for rows.Next() {
-		err = rows.Scan(&name, &oid)
-		if err != nil {
-			log.Fatal(err)
-		}
-		fmt.Fprintf(w, "T_%s Oid = %d\n", name, oid)
-	}
-	if err = rows.Err(); err != nil {
-		log.Fatal(err)
+	for _, oid := range oids {
+		fmt.Fprintf(w, "T_%s Oid = %d\n", oid.Type, oid.ID)
 	}
 	fmt.Fprintln(w, ")")
+	fmt.Fprintln(w, "var TypeName = map[Oid]string{")
+	for _, oid := range oids {
+		fmt.Fprintf(w, "T_%s: \"%s\",\n", oid.Type, oid.Name())
+	}
+	fmt.Fprintln(w, "}")
 	w.Close()
 	cmd.Wait()
 }