Add simple protocol suuport with (Query|Exec)Ex

query.go

@@ -7,6 +7,7 @@ import (
 	"fmt"
 	"time"
 
+	"github.com/jackc/pgx/internal/sanitize"
 	"github.com/jackc/pgx/pgtype"
 )
 
@@ -123,6 +124,17 @@ func (rows *Rows) Next() bool {
 		}
 
 		switch t {
+		case rowDescription:
+			rows.fields = rows.conn.rxRowDescription(r)
+			for i := range rows.fields {
+				if dt, ok := rows.conn.ConnInfo.DataTypeForOid(rows.fields[i].DataType); ok {
+					rows.fields[i].DataTypeName = dt.Name
+					rows.fields[i].FormatCode = TextFormatCode
+				} else {
+					rows.Fatal(fmt.Errorf("unknown oid: %d", rows.fields[i].DataType))
+					return false
+				}
+			}
 		case dataRow:
 			fieldCount := r.readInt16()
 			if int(fieldCount) != len(rows.fields) {
@@ -341,7 +353,7 @@ func (rows *Rows) AfterClose(f func(*Rows)) {
 // be returned in an error state. So it is allowed to ignore the error returned
 // from Query and handle it in *Rows.
 func (c *Conn) Query(sql string, args ...interface{}) (*Rows, error) {
-	return c.QueryContext(context.Background(), sql, args...)
+	return c.QueryEx(context.Background(), sql, nil, args...)
 }
 
 func (c *Conn) getRows(sql string, args []interface{}) *Rows {
@@ -368,7 +380,11 @@ func (c *Conn) QueryRow(sql string, args ...interface{}) *Row {
 	return (*Row)(rows)
 }
 
-func (c *Conn) QueryContext(ctx context.Context, sql string, args ...interface{}) (rows *Rows, err error) {
+type QueryExOptions struct {
+	SimpleProtocol bool
+}
+
+func (c *Conn) QueryEx(ctx context.Context, sql string, options *QueryExOptions, args ...interface{}) (rows *Rows, err error) {
 	err = c.waitForPreviousCancelQuery(ctx)
 	if err != nil {
 		return nil, err
@@ -384,6 +400,22 @@ func (c *Conn) QueryContext(ctx context.Context, sql string, args ...interface{}
 	}
 	rows.unlockConn = true
 
+	if options != nil && options.SimpleProtocol {
+		err = c.initContext(ctx)
+		if err != nil {
+			rows.Fatal(err)
+			return rows, err
+		}
+
+		err = c.sanitizeAndSendSimpleQuery(sql, args...)
+		if err != nil {
+			rows.Fatal(err)
+			return rows, err
+		}
+
+		return rows, nil
+	}
+
 	ps, ok := c.preparedStatements[sql]
 	if !ok {
 		var err error
@@ -411,7 +443,32 @@ func (c *Conn) QueryContext(ctx context.Context, sql string, args ...interface{}
 	return rows, err
 }
 
-func (c *Conn) QueryRowContext(ctx context.Context, sql string, args ...interface{}) *Row {
-	rows, _ := c.QueryContext(ctx, sql, args...)
+func (c *Conn) sanitizeAndSendSimpleQuery(sql string, args ...interface{}) (err error) {
+	if c.RuntimeParams["standard_conforming_strings"] != "on" {
+		return errors.New("simple protocol queries must be run with standard_conforming_strings=on")
+	}
+
+	if c.RuntimeParams["client_encoding"] != "UTF8" {
+		return errors.New("simple protocol queries must be run with client_encoding=UTF8")
+	}
+
+	valueArgs := make([]interface{}, len(args))
+	for i, a := range args {
+		valueArgs[i], err = convertSimpleArgument(c.ConnInfo, a)
+		if err != nil {
+			return err
+		}
+	}
+
+	sql, err = sanitize.SanitizeSQL(sql, valueArgs...)
+	if err != nil {
+		return err
+	}
+
+	return c.sendSimpleQuery(sql)
+}
+
+func (c *Conn) QueryRowEx(ctx context.Context, sql string, options *QueryExOptions, args ...interface{}) *Row {
+	rows, _ := c.QueryEx(ctx, sql, options, args...)
 	return (*Row)(rows)
 }