You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: convert.go
    path of file: ./repos/tidb/pkg/server/internal/column
    
    the code of the file until where you have to start completion: // Copyright 2023 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,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the s
    
func ConvertColumnInfo(fld *ast.ResultField) (ci *Info) {
	ci = &Info{
		Name:         fld.ColumnAsName.O,
		OrgName:      fld.Column.Name.O,
		Table:        fld.TableAsName.O,
		Schema:       fld.DBName.O,
		Flag:         uint16(fld.Column.GetFlag()),
		Charset:      uint16(mysql.CharsetNameToID(fld.Column.GetCharset())),
		Type:         fld.Column.GetType(),
		DefaultValue: fld.Column.GetDefaultValue(),
	}

	if fld.EmptyOrgName {
		ci.OrgName = ""
	}
	if fld.Table != nil {
		ci.OrgTable = fld.Table.Name.O
	}
	if fld.Column.GetFlen() != types.UnspecifiedLength {
		ci.ColumnLength = uint32(fld.Column.GetFlen())
	}
	if fld.Column.GetType() == mysql.TypeNewDecimal {
		// Consider the negative sign.
		ci.ColumnLength++
		if fld.Column.GetDecimal() > types.DefaultFsp {
			// Consider the decimal point.
			ci.ColumnLength++
		}
	} else if types.IsString(fld.Column.GetType()) ||
		fld.Column.GetType() == mysql.TypeEnum || fld.Column.GetType() == mysql.TypeSet { // issue #18870
		// Fix issue #4540.
		// The flen is a hint, not a precise value, so most client will not use the value.
		// But we found in rare MySQL client, like Navicat for MySQL(version before 12) will truncate
		// the `show create table` result. To fix this case, we must use a large enough flen to prevent
		// the truncation, in MySQL, it will multiply bytes length by a multiple based on character set.
		// For examples:
		// * latin, the multiple is 1
		// * gb2312, the multiple is 2
		// * Utf-8, the multiple is 3
		// * utf8mb4, the multiple is 4
		// We used to check non-string types to avoid the truncation problem in some MySQL
		// client such as Navicat. Now we only allow string type enter this branch.
		charsetDesc, err := charset.GetCharsetInfo(fld.Column.GetCharset())
		if err != nil {
			ci.ColumnLength *= 4
		} else {
			ci.ColumnLength *= uint32(charsetDesc.Maxlen)
		}
	}

	if fld.Column.GetDecimal() == types.UnspecifiedLength {
		if fld.Column.GetType() == mysql.TypeDuration {
			ci.Decimal = uint8(types.DefaultFsp)
		} else {
			ci.Decimal = mysql.NotFixedDec
		}
	} else {
		ci.Decimal = uint8(fld.Column.GetDecimal())
	}

	// Keep things compatible for old clients.
	// Refer to mysql-server/sql/protocol.cc send_result_set_metadata()
	if ci.Type == mysql.TypeVarchar {
		ci.Type = mysql.TypeVarString
	}
	return
}