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Add aggregrate functions to GQL queries

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This commit is contained in:
Vikram Rangnekar
2019-03-31 11:18:33 -04:00
parent 4cebe9cfb0
commit 89d435640b
4 changed files with 167 additions and 50 deletions
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163
psql/psql.go
View File

@ -109,8 +109,6 @@ type selectBlock struct {
func (v *selectBlock) render(w io.Writer,
schema *DBSchema, childCols []*qcode.Column, childIDs []int) error {
isNotRoot := (v.parent != nil)
hasFilters := (v.sel.Where != nil)
hasOrder := len(v.sel.OrderBy) != 0
// SELECT
@ -156,46 +154,11 @@ func (v *selectBlock) render(w io.Writer,
}
// END-SELECT
// FROM
io.WriteString(w, " FROM (SELECT ")
// Local column names
v.renderLocalColumns(w, append(v.sel.Cols, childCols...))
fmt.Fprintf(w, ` FROM "%s"`, v.sel.Table)
if isNotRoot || hasFilters {
if isNotRoot {
v.renderJoinTable(w, schema, childIDs)
}
io.WriteString(w, ` WHERE (`)
if isNotRoot {
v.renderRelationship(w, schema)
}
if hasFilters {
err := v.renderWhere(w)
if err != nil {
return err
}
}
io.WriteString(w, `)`)
// FROM (SELECT .... )
err = v.renderBaseSelect(w, schema, childCols, childIDs)
if err != nil {
return err
}
if len(v.sel.Paging.Limit) != 0 {
fmt.Fprintf(w, ` LIMIT ('%s') :: integer`, v.sel.Paging.Limit)
} else {
io.WriteString(w, ` LIMIT ('20') :: integer`)
}
if len(v.sel.Paging.Offset) != 0 {
fmt.Fprintf(w, ` OFFSET ('%s') :: integer`, v.sel.Paging.Offset)
}
fmt.Fprintf(w, `) AS "%s_%d"`, v.sel.Table, v.sel.ID)
// END-FROM
return nil
@ -297,18 +260,94 @@ func (v *selectBlock) renderJoinedColumns(w io.Writer, childIDs []int) error {
return nil
}
func (v *selectBlock) renderLocalColumns(w io.Writer, columns []*qcode.Column) {
for i, col := range columns {
if len(col.Table) != 0 {
fmt.Fprintf(w, `"%s"."%s"`, col.Table, col.Name)
} else {
fmt.Fprintf(w, `"%s"."%s"`, v.sel.Table, col.Name)
func (v *selectBlock) renderBaseSelect(w io.Writer, schema *DBSchema, childCols []*qcode.Column, childIDs []int) error {
var groupBy []int
isNotRoot := (v.parent != nil)
hasFilters := (v.sel.Where != nil)
io.WriteString(w, " FROM (SELECT ")
for i, col := range v.sel.Cols {
cn := col.Name
fn := ""
if _, ok := v.schema.ColMap[TCKey{v.sel.Table, cn}]; !ok {
pl := funcPrefixLen(cn)
if pl == 0 {
continue
}
fn = cn[0 : pl-1]
cn = cn[pl:]
}
if i < len(columns)-1 {
if len(fn) != 0 {
fmt.Fprintf(w, `%s("%s"."%s") AS %s`, fn, v.sel.Table, cn, col.Name)
} else {
groupBy = append(groupBy, i)
fmt.Fprintf(w, `"%s"."%s"`, v.sel.Table, cn)
}
if i < len(v.sel.Cols)-1 || len(childCols) != 0 {
io.WriteString(w, ", ")
}
}
for i, col := range childCols {
fmt.Fprintf(w, `"%s"."%s"`, col.Table, col.Name)
if i < len(childCols)-1 {
io.WriteString(w, ", ")
}
}
fmt.Fprintf(w, ` FROM "%s"`, v.sel.Table)
if isNotRoot || hasFilters {
if isNotRoot {
v.renderJoinTable(w, schema, childIDs)
}
io.WriteString(w, ` WHERE (`)
if isNotRoot {
v.renderRelationship(w, schema)
}
if hasFilters {
err := v.renderWhere(w)
if err != nil {
return err
}
}
io.WriteString(w, `)`)
}
if len(groupBy) != 0 {
fmt.Fprintf(w, ` GROUP BY `)
for i, id := range groupBy {
fmt.Fprintf(w, `"%s"."%s"`, v.sel.Table, v.sel.Cols[id].Name)
if i < len(groupBy)-1 {
io.WriteString(w, ", ")
}
}
}
if len(v.sel.Paging.Limit) != 0 {
fmt.Fprintf(w, ` LIMIT ('%s') :: integer`, v.sel.Paging.Limit)
} else {
io.WriteString(w, ` LIMIT ('20') :: integer`)
}
if len(v.sel.Paging.Offset) != 0 {
fmt.Fprintf(w, ` OFFSET ('%s') :: integer`, v.sel.Paging.Offset)
}
fmt.Fprintf(w, `) AS "%s_%d"`, v.sel.Table, v.sel.ID)
return nil
}
func (v *selectBlock) renderOrderByColumns(w io.Writer) {
@ -549,3 +588,31 @@ func renderVal(w io.Writer, ex *qcode.Exp, vars Variables) {
}
io.WriteString(w, `)`)
}
func funcPrefixLen(fn string) int {
switch {
case strings.HasPrefix(fn, "avg_"):
return 4
case strings.HasPrefix(fn, "count_"):
return 6
case strings.HasPrefix(fn, "max_"):
return 4
case strings.HasPrefix(fn, "min_"):
return 4
case strings.HasPrefix(fn, "sum_"):
return 4
case strings.HasPrefix(fn, "stddev_"):
return 7
case strings.HasPrefix(fn, "stddev_pop_"):
return 11
case strings.HasPrefix(fn, "stddev_samp_"):
return 12
case strings.HasPrefix(fn, "variance_"):
return 9
case strings.HasPrefix(fn, "var_pop_"):
return 8
case strings.HasPrefix(fn, "var_samp_"):
return 9
}
return 0
}

20
psql/psql_test.go
View File

@ -317,6 +317,26 @@ func TestCompileGQLManyToManyReverse(t *testing.T) {
}
}
func TestCompileGQLAggFunction(t *testing.T) {
gql := `query {
products {
name
count_price
}
}`
sql := `SELECT json_object_agg('products', products) FROM (SELECT coalesce(json_agg("products"), '[]') AS "products" FROM (SELECT row_to_json((SELECT "sel_0" FROM (SELECT "products_0"."name" AS "name", "products_0"."count_price" AS "count_price") AS "sel_0")) AS "products" FROM (SELECT "products"."name", count("products"."price") AS count_price FROM "products" GROUP BY "products"."name" LIMIT ('20') :: integer) AS "products_0" LIMIT ('20') :: integer) AS "products_0") AS "done_1337";`
resSQL, err := compileGQLToPSQL(gql)
if err != nil {
t.Fatal(err)
}
if resSQL != sql {
t.Fatal(errNotExpected)
}
}
func BenchmarkCompileGQLToSQL(b *testing.B) {
gql := `query {
products(