2 files changed, 74 insertions, 10 deletions

diff --git a/pkg/datamaps/reader.go b/pkg/datamaps/reader.go
index 050853a..61771c0 100644
--- a/pkg/datamaps/reader.go
+++ b/pkg/datamaps/reader.go
@@ -147,7 +147,9 @@ func ReadXLSX(ssheet string) FileData {
 	return outer
 }
 
-func DMLFromDB(name string, db *sql.DB) []DatamapLine {
+// DMLFromDB fetches a slice of DatamapLine from the database given
+// the name of a datamap.
+func DMLFromDB(name string, db *sql.DB) ([]DatamapLine, error) {
 
 	var out []DatamapLine
 
@@ -159,7 +161,7 @@ func DMLFromDB(name string, db *sql.DB) []DatamapLine {
 	`
 	rows, err := db.Query(query, name)
 	if err != nil {
-		log.Fatal(err)
+		return nil, err
 	}
 	defer rows.Close()
 
@@ -170,20 +172,39 @@ func DMLFromDB(name string, db *sql.DB) []DatamapLine {
 			cellref string
 		)
 		if err := rows.Scan(&key, &sheet, &cellref); err != nil {
-			log.Fatal(err)
+			return nil, err
 		}
 
-		// log.Printf("key %s\nsheet %s\ncellref %v", key, sheet, cellref)
 		out = append(out, DatamapLine{Key: key, Sheet: sheet, Cellref: cellref})
 	}
 
-	return out
+	return out, nil
 }
 
-// func ExtractDBDM(name string, file string) ExtractedData {
-// 	xdata := ReadXLSX(file)
-// 	// ddata, err := DMLFromDB(name) // this will need to return a []DatamapLine
-// }
+func ExtractDBDM(name string, file string, db *sql.DB) ExtractedData {
+	xdata := ReadXLSX(file)
+	ddata, err := DMLFromDB(name, db) // this will need to return a []DatamapLine
+
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	names := getSheetNames(ddata)
+	outer := make(ExtractedData, len(names))
+	inner := make(map[string]xlsx.Cell)
+
+	for _, i := range ddata {
+		sheet := i.Sheet
+		cellref := i.Cellref
+
+		if val, ok := xdata[sheet][cellref]; ok {
+			inner[cellref] = *val.Cell
+			outer[sheet] = inner
+		}
+	}
+
+	return outer
+}
 
 //Extract returns the file's data as a map,
 // using the datamap as a filter, keyed on sheet name. All values
diff --git a/pkg/datamaps/reader_test.go b/pkg/datamaps/reader_test.go
index ec158a1..de169dd 100644
--- a/pkg/datamaps/reader_test.go
+++ b/pkg/datamaps/reader_test.go
@@ -125,7 +125,7 @@ func TestDMLSliceFromDatabase(t *testing.T) {
 		{7, "Parrots Name"},
 	}
 
-	data := DMLFromDB("First Datamap", db)
+	data, _ := DMLFromDB("First Datamap", db)
 
 	for _, c := range cases {
 		got := data[c.index].Key
@@ -139,6 +139,49 @@ func TestDMLSliceFromDatabase(t *testing.T) {
 	}
 }
 
+func TestExtractUsingDBDM(t *testing.T) {
+	// setup - we need the datamap in the test database
+	db, err := SetupDB("./testdata/test.db")
+	defer db.Close()
+
+	if err != nil {
+		t.Fatal("Expected to be able to set up the database.")
+	}
+
+	opts := Options{
+		DBPath: "./testdata/test.db",
+		DMName: "First Datamap",
+		DMPath: "./testdata/datamap.csv",
+	}
+
+	if err := DatamapToDB(&opts); err != nil {
+		t.Errorf("Unable to write datamap to database file because %v.", err)
+	}
+
+	d := ExtractDBDM("First Datamap", "testdata/test_template.xlsx", db)
+	cases := []struct {
+		sheet, cellref, val string
+	}{
+		{"Introduction", "C9", "Test Department"},
+		{"Introduction", "J9", "Greedy Parrots"},
+		{"Introduction", "A1", "10"},
+		{"Introduction", "C22", "VUNT"},
+	}
+
+	for _, c := range cases {
+		got := d[c.sheet][c.cellref].Value
+		if got != c.val {
+			t.Errorf("The test expected %s in %s sheet to be %s "+
+				"- instead it is %s.", c.sheet, c.cellref, c.val,
+				d[c.sheet][c.cellref].Value)
+		}
+	}
+
+	if d["Another Sheet"]["E26"].Value != "Integer:" {
+		t.Errorf("Expected E26 in Another Sheet sheet to be Integer: - instead it is %s", d["Another Sheet"]["E26"].Value)
+	}
+}
+
 func TestExtract(t *testing.T) {
 	d := Extract("testdata/datamap.csv", "testdata/test_template.xlsx")
 	cases := []struct {