forkjo/vendor/github.com/pingcap/tidb/mysql/util.go

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// Copyright 2015 PingCAP, Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// See the License for the specific language governing permissions and
// limitations under the License.
package mysql
// GetDefaultFieldLength is used for Interger Types, Flen is the display length.
// Call this when no Flen assigned in ddl.
// or column value is calculated from an expression.
// For example: "select count(*) from t;", the column type is int64 and Flen in ResultField will be 21.
// See: https://dev.mysql.com/doc/refman/5.7/en/storage-requirements.html
func GetDefaultFieldLength(tp byte) int {
switch tp {
case TypeTiny:
return 4
case TypeShort:
return 6
case TypeInt24:
return 9
case TypeLong:
return 11
case TypeLonglong:
return 21
case TypeDecimal:
// See: https://dev.mysql.com/doc/refman/5.7/en/fixed-point-types.html
return 10
case TypeBit, TypeBlob:
return -1
default:
//TODO: add more types
return -1
}
}
// GetDefaultDecimal returns the default decimal length for column.
func GetDefaultDecimal(tp byte) int {
switch tp {
case TypeDecimal:
// See: https://dev.mysql.com/doc/refman/5.7/en/fixed-point-types.html
return 0
default:
//TODO: add more types
return -1
}
}