regexp.go

package utils

import (
	"regexp"
)

// ExtractTableName from sql statement
func ExtractTableName(fromSQL string) (table string) {
	tableNames := make([]string, 0)
	reg := "(\\s+FROM\\s+\\`(?P<table1>\\w+)\\`\\s+((\\w+)\\s+)?(WHERE|LEFT|JOIN|INNER|ORDER))|(\\s+JOIN\\s+\\`(?P<table2>\\w+)\\`\\s+((\\w+)\\s+)?ON)"
	r, _ := regexp.Compile(reg)
	n1 := r.SubexpNames()
	finds := r.FindAllStringSubmatch(fromSQL, -1)
	for _, v := range finds {
		for ii, vv := range v {
			if n1[ii] != "" && vv != "" {
				tableNames = append(tableNames, removeDigitsFromString(vv))
			}
		}
	}
	// only return first table name.
	if len(tableNames) == 0 { // not extract any table
		table = "not query sql."
	} else {
		table = tableNames[0]
	}
	return table
}

func removeDigitsFromString(str string) (ret string) {
	r, _ := regexp.Compile(`_\d+`)
	ret = r.ReplaceAllString(str, "")
	return ret
}