Refactor sqlite schema

dialects/sqlite/schema.go

@@ -1,7 +1,7 @@
 package sqlite
 
 import (
-	"strings"
+	"fmt"
 )
 
 // AutoMigrate auto migrate database
@@ -18,30 +18,65 @@ func (dialect *Dialect) AutoMigrate(value interface{}) (err error) {
 	return nil
 }
 
-// HasTable check if has table in current schema
-func (dialect *Dialect) HasTable(tableName string) bool {
-	var count int
-	currentDatabase, tableName := currentDatabaseAndTable(dialect, tableName)
-	_ = dialect.DB.QueryRow("SELECT count(*) FROM INFORMATION_SCHEMA.TABLES WHERE table_schema = ? AND table_name = ?", currentDatabase, tableName).Scan(&count)
-	return count > 0
-}
-
 // CreateTable create table for value
 func (dialect *Dialect) CreateTable(value interface{}) error {
 	// s := schema.Parse(value)
 	return nil
 }
 
-// CurrentDatabase get current database name
-func (dialect *Dialect) CurrentDatabase() (name string) {
-	_ = dialect.DB.QueryRow("SELECT DATABASE()").Scan(&name)
-	return
+// HasTable check if has table
+func (dialect *Dialect) HasTable(tableName string) bool {
+	var count int
+	_ = dialect.DB.QueryRow("SELECT count(*) FROM sqlite_master WHERE type='table' AND name=?", tableName).Scan(&count)
+	return count > 0
 }
 
-func currentDatabaseAndTable(dialect *Dialect, tableName string) (string, string) {
-	if strings.Contains(tableName, ".") {
-		splitStrings := strings.SplitN(tableName, ".", 2)
-		return splitStrings[0], splitStrings[1]
-	}
-	return dialect.CurrentDatabase(), tableName
+// HasColumn check if has column in table
+func (dialect *Dialect) HasColumn(tableName string, columnName string) bool {
+	var count int
+	_ = dialect.DB.QueryRow(fmt.Sprintf("SELECT count(*) FROM sqlite_master WHERE tbl_name = ? AND (sql LIKE '%%\"%v\" %%' OR sql LIKE '%%%v %%');\n", columnName, columnName), tableName).Scan(&count)
+	return count > 0
+}
+
+// HasIndex check if has index in table
+func (dialect *Dialect) HasIndex(tableName string, indexName string) bool {
+	var count int
+	_ = dialect.DB.QueryRow(fmt.Sprintf("SELECT count(*) FROM sqlite_master WHERE tbl_name = ? AND sql LIKE '%%INDEX %v ON%%'", indexName), tableName).Scan(&count)
+	return count > 0
+}
+
+// HasForeignKey check if has foreign key in table
+func (dialect *Dialect) HasForeignKey(tableName string, foreignKeyName string) bool {
+	return false
+}
+
+// RemoveIndex remove index from table
+func (dialect *Dialect) RemoveIndex(tableName string, indexName string) error {
+	_, err := dialect.DB.Exec(fmt.Sprintf("DROP INDEX %v", indexName))
+	return err
+}
+
+// ModifyColumn modify column
+func (dialect *Dialect) ModifyColumn(tableName string, columnName string, typ string) error {
+	_, err := dialect.DB.Exec(fmt.Sprintf("ALTER TABLE %v ALTER COLUMN %v TYPE %v", tableName, columnName, typ))
+	return err
+}
+
+// CurrentDatabase get current database name
+func (dialect *Dialect) CurrentDatabase() (name string) {
+	var (
+		ifaces   = make([]interface{}, 3)
+		pointers = make([]*string, 3)
+		i        int
+	)
+	for i = 0; i < 3; i++ {
+		ifaces[i] = &pointers[i]
+	}
+	if err := dialect.DB.QueryRow("PRAGMA database_list").Scan(ifaces...); err != nil {
+		return
+	}
+	if pointers[1] != nil {
+		name = *pointers[1]
+	}
+	return
 }