Add StringColumn type and expression

Add Projection type
Alias refactoring
More numeric operations

generator/metadata/column_info.go

@@ -26,6 +26,31 @@ func (c ColumnInfo) ToGoVarName() string {
 	return snaker.SnakeToCamel(c.Name) + "Column"
 }
 
+func (c ColumnInfo) ToSqlBuilderColumnType() string {
+	switch c.DataType {
+	case "boolean":
+		return "BoolColumn"
+	case "smallint":
+		return "IntegerColumn"
+	case "integer":
+		return "IntegerColumn"
+	case "bigint":
+		return "IntegerColumn"
+	case "date", "timestamp without time zone", "timestamp with time zone":
+		return "StringColumn"
+	case "bytea":
+		return "StringColumn"
+	case "text":
+		return "StringColumn"
+	case "real":
+		return "NumericColumn"
+	case "numeric", "double precision":
+		return "NumericColumn"
+	default:
+		return "StringColumn"
+	}
+}
+
 func (c ColumnInfo) ToGoType() string {
 	typeStr := c.GoBaseType()
 	if c.IsNullable || c.TableInfo.IsForeignKey(c.Name) {

generator/templates.go

@@ -11,7 +11,7 @@ type {{.ToGoStructName}} struct {
 	
 	//Columns
 {{- range .Columns}}
-	{{.ToGoFieldName}} sqlbuilder.NonAliasColumn
+	{{.ToGoFieldName}} *sqlbuilder.{{.ToSqlBuilderColumnType}}
 {{- end}}
 
 	AllColumns sqlbuilder.ColumnList
@@ -22,7 +22,7 @@ var {{.ToGoVarName}} = new{{.ToGoStructName}}()
 func new{{.ToGoStructName}}() *{{.ToGoStructName}} {
 	var (
 	{{- range .Columns}}
-		{{.ToGoVarName}} = sqlbuilder.IntColumn("{{.Name}}", {{if .IsNullable}}sqlbuilder.Nullable{{else}}sqlbuilder.NotNullable{{end}})
+		{{.ToGoVarName}} = sqlbuilder.New{{.ToSqlBuilderColumnType}}("{{.Name}}", {{if .IsNullable}}sqlbuilder.Nullable{{else}}sqlbuilder.NotNullable{{end}})
 	{{- end}}
 	)