update README.md

Author: billcheng

README.md

@@ -7,12 +7,121 @@ sqlparser
 ## Usage
 
 import (
-    "github.com/Bill-cc/go-sql2struct"
+    sqlparser "github.com/Bill-cc/go-sql2struct"
 )
 
 ## example
 
 [parse_test.go](parse_test.go)
 
 [parse_next_test.go](parse_next_test.go)
-...
+...
+
+## SQL convert
+```
+// Mysql type to golang type
+var typeForMysqlToGo = map[string]string{
+	"int":                "int64",
+	"integer":            "int64",
+	"tinyint":            "int64",
+	"smallint":           "int64",
+	"mediumint":          "int64",
+	"bigint":             "int64",
+	"int unsigned":       "int64",
+	"integer unsigned":   "int64",
+	"tinyint unsigned":   "int64",
+	"smallint unsigned":  "int64",
+	"mediumint unsigned": "int64",
+	"bigint unsigned":    "int64",
+	"bit":                "int64",
+	"bool":               "bool",
+	"enum":               "string",
+	"set":                "string",
+	"varchar":            "string",
+	"char":               "string",
+	"tinytext":           "string",
+	"mediumtext":         "string",
+	"text":               "string",
+	"longtext":           "string",
+	"blob":               "string",
+	"tinyblob":           "string",
+	"mediumblob":         "string",
+	"longblob":           "string",
+	"date":               "string",
+	"datetime":           "string",
+	"timestamp":          "string",
+	"time":               "string",
+	"float":              "float64",
+	"double":             "float64",
+	"decimal":            "float64",
+	"binary":             "string",
+	"varbinary":          "string",
+}
+
+// Obtain SQL info
+func parseSQLToStruct(sqlPath string) error {
+	// convert abs path
+	sqlPathAbs, err := filepath.Abs(sqlPath)
+	if err != nil {
+		return fmt.Errorf("Get sql file filepath.Abs failed, %s", err)
+	}
+	fmt.Printf("SQL file path : %s\n", sqlPathAbs)
+
+	// sql script
+	sqlContent, err := readFileContent(sqlPathAbs)
+	if err != nil {
+		return err
+	}
+
+	// piece of sql script
+	pieces, err := sqlparser.SplitStatementToPieces(sqlContent)
+	if err != nil {
+		return fmt.Errorf("sqlparser.SplitStatementToPieces fail : %v", err)
+	}
+	for _, sql := range pieces {
+		stat, err := sqlparser.ParseStrictDDL(sql)
+		if err != nil {
+			fmt.Printf("sqlparser.Parse : %s\nerror : %v \n", sql, err)
+		}
+
+		// convert ot DDL
+		ddl, ok := stat.(*sqlparser.DDL)
+        // process DDL as CREATE TABLE
+		if ok && ddl.Action.ToString() == sqlparser.CreateStr {
+			// table info
+			sqlInfo := SQLInfo{}
+			sqlInfo.SQLContent = sql
+			sqlInfo.TableName = ddl.Table.Name.String()
+			sqlInfo.TableNameStd = Marshal(sqlInfo.TableName)
+			// table column
+			for _, col := range ddl.TableSpec.Columns {
+				colInfo := ColInfo{}
+				// Autoincrement 
+				colInfo.Autoincrement = col.Type.Autoincrement
+				// field define
+				buf := sqlparser.NewTrackedBuffer(nil)
+				col.Type.Format(buf)
+				colInfo.ColContent = buf.String()
+				// field name
+				colInfo.Name = col.Name.String()
+				// field name hump
+				colInfo.NameStd = Marshal(colInfo.Name)
+				if colInfo.Autoincrement {
+					sqlInfo.AutoCol = colInfo.Name
+				}
+				// comment
+				if col.Type.Comment != nil {
+					colInfo.Comment = sqlparser.String(col.Type.Comment)
+				}
+				// Mysql type
+				colInfo.Type = col.Type.Type
+				// Golang tyoe
+				colInfo.GoType = typeForMysqlToGo[colInfo.Type]
+				sqlInfo.ColInfos = append(sqlInfo.ColInfos, colInfo)
+			}
+			sqlInfoList = append(sqlInfoList, sqlInfo)
+		}
+	}
+	return nil
+}
+```