feat: enhance query builder with improved alias handling (#285)

* feat: enhance query builder with improved alias handling

- Updated `quote` function to handle SQL expressions with aliases more robustly.
- Added support for quoting function expressions like `COUNT(id) as count` and `MAX(id) as maxId`.
- Improved test coverage by adding a test case for `select count` in both v1 and v2 test suites.
- Ensured consistent quoting of standalone identifiers and expressions in query generation.

This change improves the flexibility and correctness of SQL query generation, particularly in handling complex expressions with aliases.

* v0.30.1

allographer.nimble

@@ -1,6 +1,6 @@
 # Package
 
-version       = "0.30.0"
+version       = "0.30.1"
 author        = "Hidenobu Itsumura @dumblepytech1 as 'medy'"
 description   = "A Nim query builder library inspired by Laravel/PHP and Orator/Python"
 license       = "MIT"

src/allographer/v1/query_builder/models/postgres/query/postgres_generator.nim

@@ -7,13 +7,35 @@ import ../postgres_types
 
 proc quote(input:string):string =
   ## `User.id as userId` => `"User"."id" as "userId"`
+  ##
+  ## `COUNT(id) as count` => `COUNT("id") as "count"`
+  ##
+  ## `MAX(id) as maxId` => `MAX("id") as "maxId"`
+  ##
+
   var tmp = newSeq[string]()
-  for row in input.split("."):
-    if row.contains(" as "):
-      let c = row.split(" as ")
-      tmp.add(&"\"{c[0]}\" as \"{c[1]}\"")
+  for segment in input.split("."):
+    if segment.contains(" as "):
+      # Split once on ' as ' to separate the expression and its alias
+      let parts = segment.split(" as ", maxsplit = 1)
+      let expression = parts[0]
+      let alias = parts[1]
+      if expression.contains("("):
+        # Extract function name and column name using index-based slicing
+        let funcStart = expression.find('(')
+        let funcEnd = expression.find(')', funcStart)
+        let funcName = expression[0 ..< funcStart]
+        let columnName = expression[funcStart + 1 ..< funcEnd]
+        tmp.add(&"{funcName}(\"{columnName}\") as \"{alias}\"")
+      else:
+        # Quote the expression and alias
+        tmp.add(&"\"{expression}\" as \"{alias}\"")
+    elif segment.contains("("):
+      # Leave functions without alias as is
+      tmp.add(segment)
     else:
-      tmp.add(&"\"{row}\"")
+      # Quote standalone identifiers
+      tmp.add(&"\"{segment}\"")
   return tmp.join(".")
 
 
@@ -31,8 +53,7 @@ proc selectSql*(self: PostgresQuery): PostgresQuery =
     for i, item in self.query["select"].getElems():
       if i > 0: queryString.add(",")
       var column = item.getStr()
-      if column != "*":
-        column = quote(column)
+      if column != "*": column = quote(column)
       queryString.add(&" {column}")
   else:
     queryString.add(" *")

src/allographer/v2/query_builder/models/postgres/query/postgres_generator.nim

@@ -6,13 +6,35 @@ import ../postgres_types
 
 proc quote(input:string):string =
   ## `User.id as userId` => `"User"."id" as "userId"`
+  ##
+  ## `COUNT(id) as count` => `COUNT("id") as "count"`
+  ##
+  ## `MAX(id) as maxId` => `MAX("id") as "maxId"`
+  ##
+
   var tmp = newSeq[string]()
-  for row in input.split("."):
-    if row.contains(" as "):
-      let c = row.split(" as ")
-      tmp.add(&"\"{c[0]}\" as \"{c[1]}\"")
+  for segment in input.split("."):
+    if segment.contains(" as "):
+      # Split once on ' as ' to separate the expression and its alias
+      let parts = segment.split(" as ", maxsplit = 1)
+      let expression = parts[0]
+      let alias = parts[1]
+      if expression.contains("("):
+        # Extract function name and column name using index-based slicing
+        let funcStart = expression.find('(')
+        let funcEnd = expression.find(')', funcStart)
+        let funcName = expression[0 ..< funcStart]
+        let columnName = expression[funcStart + 1 ..< funcEnd]
+        tmp.add(&"{funcName}(\"{columnName}\") as \"{alias}\"")
+      else:
+        # Quote the expression and alias
+        tmp.add(&"\"{expression}\" as \"{alias}\"")
+    elif segment.contains("("):
+      # Leave functions without alias as is
+      tmp.add(segment)
     else:
-      tmp.add(&"\"{row}\"")
+      # Quote standalone identifiers
+      tmp.add(&"\"{segment}\"")
   return tmp.join(".")
 
 
@@ -30,8 +52,7 @@ proc selectSql*(self: PostgresQuery): PostgresQuery =
     for i, item in self.query["select"].getElems():
       if i > 0: queryString.add(",")
       var column = item.getStr()
-      if column != "*":
-        column = quote(column)
+      if column != "*": column = quote(column)
       queryString.add(&" {column}")
   else:
     queryString.add(" *")

tests/v1/postgres/test_query.nim

@@ -128,6 +128,11 @@ suite($rdb & " get"):
     check t == @[%*{"email":"user10@example.com"}]
 
 
+  test("select count"):
+    var t = rdb.select("COUNT(id) as count").table("user").get().waitFor
+    check t[0]["count"].getInt() == 10
+
+
   test("where"):
     var t = rdb.table("user").where("auth_id", "=", "1").get().waitFor
     check t == @[

tests/v2/postgres/test_query.nim

@@ -2,6 +2,8 @@ discard """
   cmd: "nim c -d:reset -d:ssl -r $file"
 """
 
+# nim c -d:reset -d:ssl -r tests/v2/postgres/test_query.nim
+
 import std/unittest
 import std/asyncdispatch
 import std/httpclient
@@ -128,6 +130,11 @@ suite($rdb & " get"):
     check t == @[%*{"email":"user10@example.com"}]
 
 
+  test("select count"):
+    var t = rdb.select("COUNT(id) as count").table("user").get().waitFor
+    check t[0]["count"].getInt() == 10
+
+
   test("where"):
     var t = rdb.table("user").where("auth_id", "=", "1").get().waitFor
     check t == @[