Question

我有一个带有SQL语句的数组：

    var sql=[ "select sum(custo) as TOTAL from PRS_CUSTOS_MATERIAL ",
              "select mes,sum(custo) as TOTAL from PRS_CUSTOS_MATERIAL GROUP BY mes"
   ];

我需要在每个语句中放置一个where子句。问题是当我有其他条款而不是WHERE我需要将WHERE子句放在所有其他子句之前。我试着这样做，但没有运气。

var clauses=['GROUP','HAVING'];
    _.forEach(sql, function (sq, key) {
        clauses.map(function (clause) {
            if (sq.indexOf(clause) !== -1) {
                debugger;
                sql[key]=[sq.slice(0, sq.indexOf(clause)), ' where '+obj.where_str+' ', sq.slice(sq.indexOf(clause))].join('');

                return false;
            }else{
                debugger;
                sql[key]=sq+" where " + obj.where_str;
                return false;
            }
        });
    });

Answer 1

我建议您使用RegExp解决问题。

使用以下RegExp，您可以找到Select是否具有GROUP或HAVING运算符。

var pattern = /(select.*)((?:GROUP|HAVING).*)/i;

然后你可以针对你的阵列测试这种模式：

var arr = ['select mes,sum(custo) as TOTAL from PRS_CUSTOS_MATERIAL GROUP BY mes',
    'select sum(custo) as TOTAL from PRS_CUSTOS_MATERIAL ',
    'select sum(custo) as TOTAL from PRS_CUSTOS_MATERIAL HAVING sadsa'];

arr.forEach(function(select, index){
    var n = pattern.exec(select); // execute the pattern agains the current Select
    if(!n){ // if it not match any GROUP or HAVING,
        arr[index] += arr[index] + ' your_WHERE '; // append your Where at the end
        return;
    } // if match, append yout Where in the middle
    arr[index] = n[1] + ' your_WHERE ' + n[2];
});

结果将是：

0:"select mes,sum(custo) as TOTAL from PRS_CUSTOS_MATERIAL  your_WHERE GROUP BY mes"
1:"select sum(custo) as TOTAL from PRS_CUSTOS_MATERIAL "
2:"select sum(custo) as TOTAL from PRS_CUSTOS_MATERIAL  your_WHERE HAVING sadsa"

希望它有所帮助。

Answer 2

这只是我身边的尝试..请看看。

以下代码将在from ..语句之后添加新的where子句。所以它永远是第一位的。

＆＃13;

var str= "select sum(custo) as TOTAL from PRS_CUSTOS_MATERIAL groupBy....";

var newStr = 'where something > 12' 

var first_part = str.substr(0,str.indexOf('from')+5);

var second_part_tmp = str.substr(str.indexOf('from')+6);

var second_part = second_part_tmp.substr(0,second_part_tmp.indexOf(' '));
var third_part = second_part_tmp.substr(second_part_tmp.indexOf(' '));
if(second_part.indexOf(' ')!=0){

}
console.log(first_part,second_part, third_part);
console.log([first_part,second_part,newStr,  third_part].join(' '))

＆＃13;

Answer 3

谢谢大家，但我简化了一些事情。我只是替换:where

var sql=[
                    "select sum(custo) as TOTAL from PRS_CUSTOS_MATERIAL :where",
                    "select mes,sum(custo) as TOTAL from PRS_CUSTOS_MATERIAL :where GROUP BY mes"
                ];

使用

_.forEach(sql, function (sq, key) {
        sq=sq.replace(":where", ' where '+obj.where_str);
        sql[key]=sq
    });

用Lodash替换或附加到字符串

3 个答案: