private void associateField(String sourceTableField, String sideTableField, SqlNode sqlNode) {
        String errorMsg = "can't deal equal field: " + sqlNode;
        equalFieldList.add(sideTableField);
        int equalFieldIndex = -1;
        for (int i = 0; i < rowTypeInfo.getFieldNames().length; i++) {
            String fieldName = rowTypeInfo.getFieldNames()[i];
            if (fieldName.equalsIgnoreCase(sourceTableField)) {
                equalFieldIndex = i;
            }
        }
        Preconditions.checkState(equalFieldIndex != -1, errorMsg);
        equalValIndex.add(equalFieldIndex);
    }
deal with equation with constant etc. foo.id = 1
@param literal
@param identifier
core/src/main/java/com/dtstack/flink/sql/side/BaseSideInfo.java