{{ $ref := ref . "maintenance/configurations.md" }}
Function Description
substring(column,beginInclusive)
Get column.substring(beginInclusive). Output is a STRING.
substring(column,beginInclusive,endExclusive)
Get column.substring(beginInclusive,endExclusive). Output is a STRING.
truncate(column,width)
Truncate column by width. Output type is the same with column. If the column is a STRING, truncate(column,width) will truncate the string to width characters, namely `value.substring(0, width)`. If the column is an INT or LONG, truncate(column,width) will truncate the number with the algorithm `v - (((v % W) + W) % W)`. The `redundant` compute part is to keep the result always positive. If the column is a DECIMAL, truncate(column,width) will truncate the decimal with the algorithm: let `scaled_W = decimal(W, scale(v))`, then return `v - (v % scaled_W)`.
cast(value,dataType)
Get a constant value. The output is an atomic type, such as STRING, INT, BOOLEAN, etc.
upper(value)
Convert string column to upper case. The input should be a STRING and the output is a STRING.
lower(value)
Convert string column to lower case. The input should be a STRING and the output is a STRING.
trim(value)
Trim string column. The input should be a STRING and the output is a STRING.