R/td.stats.R

In nonsleepr/teradataR: Teradata R Package

td.stats <- function(tdf, col, which = "all", type = "population", group.by = NULL) {
    if (!is.td.data.frame(tdf)) 
        stop("'tdf' is not a td data frame")
    if (!missing(group.by) && !is.td.data.frame(group.by)) 
        stop("'group.by' is not a td data frame")
    if (!length(names(tdf))) 
        stop("td.data.frame contains no columns")
    
    wc <- ""
    if (!is.null(attr(tdf, "whereClause"))) 
        wc <- paste("WHERE", attr(tdf, "whereClause"))
    
    if (missing(col)) {
        nm <- names(tdf)[1]
        col <- .td.gencolumnexpr(tdf[names(tdf)[1]])
    } else nm <- col
    
    obj <- .td.object(attr(tdf, "tableName"), attr(tdf, "database"))
    stats <- .td.genstats(col, which, type)
    if (is.null(group.by)) 
        query <- gettextf("SELECT '%s' as col,%s FROM %s %s", nm, paste(stats, collapse = ","), obj, wc) else {
        gb <- paste("\"", names(group.by), "\"", sep = "", collapse = ",")
        query <- gettextf("SELECT %s,'%s' as col,%s FROM %s %s GROUP BY %s ORDER BY %s", gb, nm, paste(stats, collapse = ","), 
            obj, wc, gb, gb)
    }
    df <- tdQuery(query)
    if (is.data.frame(df)) 
        return(df)
    return(df[1])
}