Resolve column position modification (#20)

* Resolve column position modificication

* bug fix

* update version

* update CHANGELOG

CHANGELOG.md

@@ -1,3 +1,24 @@
+## 0.4.2 (2017-02-10)
+
+Minor feature released
+
+### Added
+
+- resolve column position modification 
+
+### Deprecated
+
+- Nothing
+
+### Removed
+
+- Nothing
+
+### Fixed
+
+- Fix SEGV error 
+
+
 ## 0.4.1 (2017-02-08)
 
 Add migrate table collation

builder/builder.go

@@ -58,13 +58,17 @@ func willAlterTableCharacterSet(old, new *mysql.Table) string {
 	alter := []string{}
 	if old.GetCharset() != new.GetCharset() {
 		alter = append(alter, new.ToConvertCharsetSQL())
+		old.TableCollation = new.TableCollation
 	}
-	old.TableCollation = new.TableCollation
 
 	return new.ToAlterSQL(alter)
 }
 
 func willAlterColumnCharacterSet(old, new *mysql.Table) []string {
+	if old == nil || new == nil {
+		return []string{}
+	}
+
 	newCols := new.Columns.GroupByColumnName()
 	oldCols := old.Columns.GroupByColumnName()
 	sqls := []string{}
@@ -134,18 +138,17 @@ func willModifyColumn(old, new *mysql.Table) []string {
 		oldCol := oldCols[colName]
 		oldTableSchema := oldCol.TableSchema
 		oldColumnKey := oldCol.ColumnKey
-		oldOrdinalPosition := oldCol.OrdinalPosition
 		oldPrivileges := oldCol.Privileges
 		oldCol.TableSchema = newCol.TableSchema
 		oldCol.ColumnKey = newCol.ColumnKey
-		oldCol.OrdinalPosition = newCol.OrdinalPosition
 		oldCol.Privileges = newCol.Privileges
 		if !reflect.DeepEqual(oldCol, newCol) {
-			sqls = append(sqls, newCol.ToModifySQL())
+			sql := newCol.ToModifySQL()
+			sql = fmt.Sprintf("%s %s", sql, newCol.AppendPos(new.Columns))
+			sqls = append(sqls, sql)
 		}
 		oldCol.TableSchema = oldTableSchema
 		oldCol.ColumnKey = oldColumnKey
-		oldCol.OrdinalPosition = oldOrdinalPosition
 		oldCol.Privileges = oldPrivileges
 	}
 	return sqls

cmd/carpenter/version.go

@@ -1,4 +1,4 @@
 package main
 
 const Name string = "carpenter"
-const Version string = "0.4.1"
+const Version string = "0.4.2"

dialect/mysql/column.go

@@ -121,21 +121,25 @@ func (m Columns) ToSQL() []string {
 	return sqls
 }
 
+func (m *Column) AppendPos(all Columns) string {
+	pos := "first"
+	if m.OrdinalPosition > 1 {
+		before := m.OrdinalPosition - 1
+		for _, v := range all {
+			if v.OrdinalPosition != before {
+				continue
+			}
+			pos = fmt.Sprintf("after %s", Quote(v.ColumnName))
+			break
+		}
+	}
+	return pos
+}
+
 func (m Columns) ToAddSQL(all Columns) []string {
 	sqls := make([]string, 0, len(m))
 	for _, col := range m {
-		pos := "first"
-		if col.OrdinalPosition > 1 {
-			before := col.OrdinalPosition - 1
-			for _, v := range all {
-				if v.OrdinalPosition != before {
-					continue
-				}
-				pos = fmt.Sprintf("after %s", Quote(v.ColumnName))
-				break
-			}
-		}
-		sqls = append(sqls, col.ToAddSQL(pos))
+		sqls = append(sqls, col.ToAddSQL(col.AppendPos(all)))
 	}
 	return sqls
 }