Adding more SQL function definition

[allwefantasy]

sql-code-intelligence provides more accurate and detailed information for function completion. However, in order to achieve this, we need function definition in SQL.
sql-code-intelligence has a mechanism that enables engineers to do this job.

For example, you can register split function in this project like the following:

class Splitter extends FuncReg {

  override def register = {
    val func = MLSQLSQLFunction.apply("split").
      funcParam.
      param("str", DataType.STRING, false, Map("zhDoc" -> "待切割字符")).
      param("pattern", DataType.STRING, false, Map("zhDoc" -> "分隔符")).
      func.
      returnParam(DataType.ARRAY, true, Map(
        "zhDoc" ->
          """
            |split函数。用于切割字符串，返回字符串数组
            |""".stripMargin
      )).
      build
    func
  }

}

Then you can put this class under the package tech.mlsql.autosuggest.funcs.
They will be autoloaded at system startup.