kds_mysql_query_writer/query-writer.js

A beginner-friendly node for writing SQL queries via input fields

module.exports = function (RED) {
  function QueryWriterNode(config) {
    RED.nodes.createNode(this, config);
    var node = this;

    function parsePayloadString(str, msg) {
      if (typeof str === "string") {
        return str.replace(/\{msg\.payload\.(\w+)\}/g, function (_, key) {
          return msg.payload[key] || ""; // payload 값이 없을 경우 빈 문자열 반환
        });
      }
      return str; // 문자열이 아닐 경우 원래 값 반환
    }

    node.on("input", function (msg) {
      var operation = config.operation; // 작업 유형
      var table = parsePayloadString(config.table, msg); // 테이블명
      var fieldsValues = Array.isArray(config.fields_values)
        ? config.fields_values.map((item) => ({
            field: parsePayloadString(item.field, msg),
            value: parsePayloadString(item.value, msg),
          }))
        : [];

      var fields = fieldsValues.map((item) => item.field);
      var values = fieldsValues.map((item) => {
        const value = item.value.trim();
        return isNaN(value) ? `'${value}'` : value; // 숫자면 그대로, 문자열이면 따옴표 추가
      });

      var condition = parsePayloadString(config.condition, msg);
      var query = "";

      switch (operation) {
        case "SELECT":
          const selectedFields = fields.length > 0 ? fields.join(", ") : "*";
          query = `SELECT ${selectedFields} FROM ${table}`;
          if (condition) query += ` WHERE ${condition}`;
          break;
        case "INSERT":
          if (fields.length === values.length && fields.length > 0) {
            query = `INSERT INTO ${table} (${fields.join(
              ", "
            )}) VALUES (${values.join(", ")})`;
          } else {
            node.error("Field and value count do not match for INSERT.");
            return;
          }
          break;
        case "UPDATE":
          if (fields.length === values.length && fields.length > 0) {
            let fieldValuePairs = fields.map(
              (field, index) => `${field}=${values[index]}`
            );
            query = `UPDATE ${table} SET ${fieldValuePairs.join(", ")}`;
            if (condition) query += ` WHERE ${condition}`;
          } else {
            node.error("Field and value count do not match for UPDATE.");
            return;
          }
          break;
        case "DELETE":
          query = `DELETE FROM ${table}`;
          if (condition) query += ` WHERE ${condition}`;
          break;
        default:
          node.error("Invalid operation type");
      }

      msg.topic = query;
      node.send(msg);
    });
  }

  RED.nodes.registerType("kds mysql query writer", QueryWriterNode);
};