Change Conn#OneValue method signature.

function_test.go

@@ -22,7 +22,8 @@ func TestScalarFunction(t *testing.T) {
 	defer db.Close()
 	err = db.CreateScalarFunction("half", 1, nil, half, nil)
 	checkNoError(t, err, "couldn't create function: %s")
-	d, err := db.OneValue("select half(6)")
+	var d float64
+	err = db.OneValue("select half(6)", &d)
 	checkNoError(t, err, "couldn't retrieve result: %s")
 	if d != 3.0 {
 		t.Errorf("Expected %f but got %f", 3.0, d)
@@ -115,9 +116,10 @@ func TestSumFunction(t *testing.T) {
 	defer db.Close()
 	err = db.CreateAggregateFunction("mysum", 1, nil, sumStep, sumFinal, nil)
 	checkNoError(t, err, "couldn't create function: %s")
-	i, err := db.OneValue("select mysum(i) from (select 2 as i union all select 2)")
+	var i int
+	err = db.OneValue("select mysum(i) from (select 2 as i union all select 2)", &i)
 	checkNoError(t, err, "couldn't execute statement: %s")
-	if i != int64(4) {
+	if i != 4 {
 		t.Errorf("Expected %d but got %v", 4, i)
 	}
 }

pragma.go

@@ -19,7 +19,8 @@ func (c *Conn) IntegrityCheck(max int, quick bool) error {
 	} else {
 		pragma = "integrity"
 	}
-	msg, err := c.OneValue(fmt.Sprintf("PRAGMA %s_check(%d)", pragma, max))
+	var msg string
+	err := c.OneValue(fmt.Sprintf("PRAGMA %s_check(%d)", pragma, max), &msg)
 	if err != nil {
 		return err
 	}
@@ -33,25 +34,21 @@ func (c *Conn) IntegrityCheck(max int, quick bool) error {
 // (See http://sqlite.org/pragma.html#pragma_encoding)
 // TODO Make possible to specify the database-name (PRAGMA %Q.encoding)
 func (c *Conn) Encoding() (string, error) {
-	value, err := c.OneValue("PRAGMA encoding")
+	var encoding string
+	err := c.OneValue("PRAGMA encoding", &encoding)
 	if err != nil {
 		return "", err
 	}
-	if encoding, ok := value.(string); ok {
 	return encoding, nil
-	}
-	return "", c.specificError("Unexpected encoding (%v)", value)
 }
 
 // (See http://sqlite.org/pragma.html#pragma_schema_version)
 // TODO Make possible to specify the database-name (PRAGMA %Q.schema_version)
-func (c *Conn) SchemaVersion() (int64, error) {
-	value, err := c.OneValue("PRAGMA schema_version")
+func (c *Conn) SchemaVersion() (int, error) {
+	var version int
+	err := c.OneValue("PRAGMA schema_version", &version)
 	if err != nil {
 		return -1, err
 	}
-	if version, ok := value.(int64); ok {
 	return version, nil
-	}
-	return -1, c.specificError("Unexpected version (%v)", value)
 }

pragma_test.go

 package sqlite_test
 
 import (
-//	. "github.com/gwenn/gosqlite"
 	"testing"
 )
 

sqlite.go

@@ -378,19 +378,19 @@ func (c *Conn) Exists(query string, args ...interface{}) (bool, error) {
 
 // Use it with SELECT that returns only one row with only one column.
 // Returns io.EOF when there is no row.
-func (c *Conn) OneValue(query string, args ...interface{}) (interface{}, error) {
+func (c *Conn) OneValue(query string, value interface{}, args ...interface{}) error {
 	s, err := c.Prepare(query, args...)
 	if err != nil {
-		return nil, err
+		return err
 	}
 	defer s.Finalize()
 	b, err := s.Next()
 	if err != nil {
-		return nil, err
+		return err
 	} else if !b {
-		return nil, io.EOF
+		return io.EOF
 	}
-	return s.ScanValue(0), nil
+	return s.Scan(value)
 }
 
 // Count the number of rows modified