Expose column decltypes from SQLiteRows iterator

sqlite3.go

@@ -505,6 +505,17 @@ func (rc *SQLiteRows) Columns() []string {
 	return rc.cols
 }
 
+// Return column decltypes.
+func (rc *SQLiteRows) DeclTypes() []string {
+	if rc.nc != len(rc.decltype) {
+		rc.decltype = make([]string, rc.nc)
+		for i := 0; i < rc.nc; i++ {
+			rc.decltype[i] = strings.ToLower(C.GoString(C.sqlite3_column_decltype(rc.s.s, C.int(i))))
+		}
+	}
+	return rc.decltype
+}
+
 // Move cursor to next.
 func (rc *SQLiteRows) Next(dest []driver.Value) error {
 	rv := C.sqlite3_step(rc.s.s)

sqlite_hook_test.go

@@ -0,0 +1,58 @@
+package sqlite3
+
+import (
+	"database/sql"
+	"database/sql/driver"
+	"os"
+	"strings"
+	"testing"
+)
+
+// Register ConnectHook, get *SQLiteRows from driver.Rows,
+// test DeclTypes() method.
+func TestDeclTypes(t *testing.T) {
+	var sqlite3conn *SQLiteConn = nil
+	sql.Register("sqlite3_with_hook_for_decltypes",
+			&SQLiteDriver{
+					ConnectHook: func(conn *SQLiteConn) error {
+						sqlite3conn = conn
+						return nil
+					},
+			})
+
+	tempFilename := TempFilename()
+	db, err := sql.Open("sqlite3_with_hook_for_decltypes", tempFilename)
+	if err != nil {
+		t.Fatal("Failed to open database:", err)
+	}
+	defer os.Remove(tempFilename)
+	defer db.Close()
+
+	db.Exec("CREATE TABLE foo (id INTEGER, d DOUBLE, dt DATETIME, b BLOB);")
+	db.Exec("INSERT INTO foo VALUES(1, 0.5, '2015-03-05 15:16:17', x'900df00d');")
+
+	if sqlite3conn == nil {
+		t.Fatal("Failed to hook into SQLiteConn")
+	}
+	rows, err := sqlite3conn.Query("SELECT * FROM foo", []driver.Value{})
+	if err != nil {
+		t.Fatal("Unable to query foo table:", err)
+	}
+	defer rows.Close()
+
+	var decltypes []string
+	switch rows.(type) {
+	case *SQLiteRows: decltypes = rows.(*SQLiteRows).DeclTypes()
+	default: t.Fatal("Failed to convert driver.Rows to *SQLiteRows")
+	}
+
+	expectedDeclTypes := []string{"INTEGER", "DOUBLE", "DATETIME", "BLOB"}
+	if len(decltypes) != len(expectedDeclTypes) {
+		t.Errorf("Number of decltypes should be %d, not %d", len(expectedDeclTypes), len(decltypes))
+	}
+	for i := 0; i < len(expectedDeclTypes); i++ {
+		if !strings.EqualFold(decltypes[i], expectedDeclTypes[i]) {
+			t.Errorf("decltype of column %d should be %s, not %s", i, expectedDeclTypes[i], decltypes[i])
+		}
+	}
+}