private void checkColumnExistsInTable(String tableName, DatabaseMetaData metaData,
      String catalogFilter, String schemaFilter, String columnName) throws SQLException {
    int caseInsensitiveMatches = 0;
    try (ResultSet columnData =
        metaData.getColumns(catalogFilter, schemaFilter, tableName, "%")) {
      while (columnData.next()) {
        String realColumnName = columnData.getString("COLUMN_NAME");
        if (columnName.equals(realColumnName)) {
          return;
        } else if (columnName.equalsIgnoreCase(realColumnName)) {
          caseInsensitiveMatches++;
        }
      }
    }
    if (caseInsensitiveMatches > 1) {
      throw new JdbcConnectorException(
          "The table " + tableName + " has more than one column that matches " + columnName);
    } else if (caseInsensitiveMatches == 0) {
      throw new JdbcConnectorException(
          "The table " + tableName + " does not have a column named " + columnName);
    }
  }
If the region mapping has been given a table name then return it.
Otherwise return the region mapping's region name as the table name.
geode-connectors/src/main/java/org/apache/geode/connectors/jdbc/internal/TableMetaDataManager.java