sp_writeTable: Write dataframe to file with names of first column filled.
In Tong-Chen/YSX: For Yishengxin Training

Write dataframe to file with names of first column filled.

1	sp_writeTable(df, file = "", keep_rownames = T, col.names = T)

`df`	A dataframe
`file`	Filename
`keep_rownames`	Default TRUE meaning output rownames as the first column with column name is `ID`. If FALSE, ignore rownames.
`col.names`	either a logical value indicating whether the column names of `x` are to be written along with `x`, or a character vector of column names to be written. See the section on ‘CSV files’ for the meaning of `col.names = NA`.