tedious/lib/token/colmetadata-token-parser.js

A TDS driver, for connecting to MS SQLServer databases.

"use strict";

const metadataParse = require('../metadata-parser');

function readTableName(parser, options, metadata, callback) {
  if (metadata.type.hasTableName) {
    if (options.tdsVersion >= '7_2') {
      parser.readUInt8(numberOfTableNameParts => {
        const tableName = [];
        let i = 0;

        function next(done) {
          if (numberOfTableNameParts === i) {
            return done();
          }

          parser.readUsVarChar(part => {
            tableName.push(part);
            i++;
            next(done);
          });
        }

        next(() => {
          callback(tableName);
        });
      });
    } else {
      parser.readUsVarChar(callback);
    }
  } else {
    callback(undefined);
  }
}

function readColumnName(parser, options, index, metadata, callback) {
  parser.readBVarChar(colName => {
    if (options.columnNameReplacer) {
      callback(options.columnNameReplacer(colName, index, metadata));
    } else if (options.camelCaseColumns) {
      callback(colName.replace(/^[A-Z]/, function (s) {
        return s.toLowerCase();
      }));
    } else {
      callback(colName);
    }
  });
}

function readColumn(parser, options, index, callback) {
  metadataParse(parser, options, metadata => {
    readTableName(parser, options, metadata, tableName => {
      readColumnName(parser, options, index, metadata, colName => {
        callback({
          userType: metadata.userType,
          flags: metadata.flags,
          type: metadata.type,
          colName: colName,
          collation: metadata.collation,
          precision: metadata.precision,
          scale: metadata.scale,
          udtInfo: metadata.udtInfo,
          dataLength: metadata.dataLength,
          tableName: tableName
        });
      });
    });
  });
}

module.exports = function (parser, colMetadata, options, callback) {
  parser.readUInt16LE(columnCount => {
    const columns = [];
    let i = 0;

    function next(done) {
      if (i === columnCount) {
        return done();
      }

      readColumn(parser, options, i, column => {
        columns.push(column);
        i++;
        next(done);
      });
    }

    next(() => {
      callback({
        name: 'COLMETADATA',
        event: 'columnMetadata',
        columns: columns
      });
    });
  });
};