parser for an SQL REPLACE INTO string

parser-for-an-sql-replace-into-string.markdown

parser for an SQL REPLACE INTO string

Needed to get keys and values into a pair of arrays for some sanitation of row data.

A Pen by Jim on CodePen.

License.

script.babel

const sampleReplaceString = "REPLACE INTO `Users` (`id`, `firstname`, `lastname`, `email`, `telephone`, `cellphone`, `active` `location`, `joined`, `last_online`) VALUES (15,'Smith','Steve','[email protected]','+1 2223331212',NULL,1,'Idaho Falls,ID','2014-10-09 14:59:56','2016-04-25 06:10:40');"

let isInteger = _.isInteger
let asInt = _.parseInt
const getKeys = str => {
  const newKeys = []
  for(let p of str.split(',')) {
    newKeys.push(p.split('`')[1])
  }
  return newKeys
}
const getValues = (values, keys) => {
  const cleanStringStart = str => {
    if (str.startsWith("'")) {
      // string to string
      str = str.slice(1, str.length);
    }
    if (str.startsWith(",")) {
      str = str.slice(1, str.length);
    }
    return str;
  };
  const getNewEnd = str => {
    let end = str.indexOf(",");
    if (str.startsWith("'")) {
      // its a string
      end = str.indexOf("',") + 1;
    }
    return end > -1 ? end : str.length;
  };

  let items = [];
  let str = values;
  for (let i = 0; i < keys.length; i++) {
    str = cleanStringStart(str);
    let newEnd = getNewEnd(str);
    items.push(str.substr(0, newEnd));
    str = str.slice(newEnd, str.length);
  }

  let cleanedValues = [];
   
  for (let value of items) {
    value = value.trim()
    if (isInteger(asInt(value)) && value.toString().includes('.')) {
      // floating point "x.xx" leave as string
      cleanedValues.push(value)
    } else if (isInteger(asInt(value)) ) {
       cleanedValues.push(asInt(value))
    } else if (value === "NULL") {
       cleanedValues.push(value)
    } else if (value.startsWith("'") && value.endsWith("'")) {
        cleanedValues.push(value.slice(1, value.length -1).trim());          
    } else {
      // something other than a string
      cleanedValues.push(value)
    }
  }
  return cleanedValues;
};

const parseSqlReplace = (str) => {
  const template = "REPLACE INTO `${ tableName }` (${ keys }) VALUES (${ values });"
  const regex = /REPLACE INTO `(.*)` \((.+)\) VALUES \((.+)\);/
  const parts = regex.exec(JSON.stringify(str))
  let tableName = parts[1]
  let keys = getKeys(parts[2])
  let values = getValues(parts[3], keys)
  return {
    keys: keys,
    values: values,
    template: template
  }
}

const cleaned = parseSqlReplace(sampleReplaceString)

console.log(cleaned)

scripts

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