sqlCol
Syntax
sqlCol(colName, [func], [alias], [qualifier])
Arguments
colName is a string scalar/vector indicating column name(s).
func (optional) is a unary function.
alias (optional) is a string scalar/vector indicating column name(s) of the selected column(s) or calculation result(s).
qualifier (optional) is a STRING scalar. It is only used in a table join operation when we need to select a column that appears in both tables and that is not a matching column. It indicates the table from which to select the column.
Details
Examples
t = table(`GME`AMC`KOSS as symbol, 325 13.26 64 as price);
colName="symbol";
sql(select=sqlCol(colName), from=t).eval();
symbol |
---|
GME |
AMC |
KOSS |
colName="price";
sql(select=sqlCol(colName, max, `maxPrice), from=t).eval();
maxPrice |
---|
325 |
t1 = table(1 2 3 3 as id, 7.8 4.6 5.1 0.1 as value, 4 3 2 1 as x);
t2 = table(5 3 1 as id, 300 500 800 as qty, 44 66 88 as x) ;
sql(select=(sqlCol(`id),sqlCol(colName=`x, alias="t1_x", qualifier="t1"),sqlCol(colName=`x, alias="t2_x", qualifier=`t2)), from=<ej(t1,t2,`id)>).eval()
id | t1_x | t2_x |
---|---|---|
1 | 4 | 88 |
3 | 2 | 66 |
3 | 1 | 66 |