From 5ba53e56c9718d2b6f44f11d6bb9cccc082d9751 Mon Sep 17 00:00:00 2001
From: John <john@johng.cn>
Date: Thu, 26 Nov 2020 22:11:58 +0800
Subject: [PATCH] improve join feature for sub-query for gdb.Model

---
 database/gdb/gdb_model_join.go | 91 ++++++++++------------------------
 1 file changed, 27 insertions(+), 64 deletions(-)

diff --git a/database/gdb/gdb_model_join.go b/database/gdb/gdb_model_join.go
index 8deab49d1..a519b3a4b 100644
--- a/database/gdb/gdb_model_join.go
+++ b/database/gdb/gdb_model_join.go
@@ -13,7 +13,7 @@ import (
 
 // isSubQuery checks and returns whether given string a sub-query sql string.
 func isSubQuery(s string) bool {
-	s = gstr.TrimLeft(s)
+	s = gstr.TrimLeft(s, "()")
 	if p := gstr.Pos(s, " "); p != -1 {
 		if gstr.Equal(s[:p], "select") {
 			return true
@@ -27,35 +27,9 @@ func isSubQuery(s string) bool {
 // and also with its alias name, like:
 // Table("user").LeftJoin("user_detail", "user_detail.uid=user.uid")
 // Table("user", "u").LeftJoin("user_detail", "ud", "ud.uid=u.uid")
+// Table("user", "u").LeftJoin("SELECT xxx FROM xxx AS a", "a.uid=u.uid")
 func (m *Model) LeftJoin(table ...string) *Model {
-	var (
-		model   = m.getModel()
-		joinStr = ""
-	)
-	if len(table) > 0 {
-		if isSubQuery(table[0]) {
-			joinStr = "(" + table[0] + ")"
-		} else {
-			joinStr = m.db.QuotePrefixTableName(table[0])
-		}
-	}
-	if len(table) > 2 {
-		model.tables += fmt.Sprintf(
-			" LEFT JOIN %s AS %s ON (%s)",
-			joinStr, m.db.QuoteWord(table[1]), table[2],
-		)
-	} else if len(table) == 2 {
-		model.tables += fmt.Sprintf(
-			" LEFT JOIN %s ON (%s)",
-			joinStr, table[1],
-		)
-	} else if len(table) == 1 {
-		model.tables += fmt.Sprintf(
-			" LEFT JOIN %s",
-			joinStr,
-		)
-	}
-	return model
+	return m.doJoin("LEFT", table...)
 }
 
 // RightJoin does "RIGHT JOIN ... ON ..." statement on the model.
@@ -63,35 +37,9 @@ func (m *Model) LeftJoin(table ...string) *Model {
 // and also with its alias name, like:
 // Table("user").RightJoin("user_detail", "user_detail.uid=user.uid")
 // Table("user", "u").RightJoin("user_detail", "ud", "ud.uid=u.uid")
+// Table("user", "u").RightJoin("SELECT xxx FROM xxx AS a", "a.uid=u.uid")
 func (m *Model) RightJoin(table ...string) *Model {
-	var (
-		model   = m.getModel()
-		joinStr = ""
-	)
-	if len(table) > 0 {
-		if isSubQuery(table[0]) {
-			joinStr = "(" + table[0] + ")"
-		} else {
-			joinStr = m.db.QuotePrefixTableName(table[0])
-		}
-	}
-	if len(table) > 2 {
-		model.tables += fmt.Sprintf(
-			" RIGHT JOIN %s AS %s ON (%s)",
-			joinStr, m.db.QuoteWord(table[1]), table[2],
-		)
-	} else if len(table) == 2 {
-		model.tables += fmt.Sprintf(
-			" RIGHT JOIN %s ON (%s)",
-			joinStr, table[1],
-		)
-	} else if len(table) == 1 {
-		model.tables += fmt.Sprintf(
-			" RIGHT JOIN %s",
-			joinStr,
-		)
-	}
-	return model
+	return m.doJoin("RIGHT", table...)
 }
 
 // InnerJoin does "INNER JOIN ... ON ..." statement on the model.
@@ -99,32 +47,47 @@ func (m *Model) RightJoin(table ...string) *Model {
 // and also with its alias name, like:
 // Table("user").InnerJoin("user_detail", "user_detail.uid=user.uid")
 // Table("user", "u").InnerJoin("user_detail", "ud", "ud.uid=u.uid")
+// Table("user", "u").InnerJoin("SELECT xxx FROM xxx AS a", "a.uid=u.uid")
 func (m *Model) InnerJoin(table ...string) *Model {
+	return m.doJoin("INNER", table...)
+}
+
+// doJoin does "LEFT/RIGHT/INNER JOIN ... ON ..." statement on the model.
+// The parameter <table> can be joined table and its joined condition,
+// and also with its alias name, like:
+// Table("user").InnerJoin("user_detail", "user_detail.uid=user.uid")
+// Table("user", "u").InnerJoin("user_detail", "ud", "ud.uid=u.uid")
+// Table("user", "u").InnerJoin("SELECT xxx FROM xxx AS a", "a.uid=u.uid")
+// Related issues:
+// https://github.com/gogf/gf/issues/1024
+func (m *Model) doJoin(operator string, table ...string) *Model {
 	var (
 		model   = m.getModel()
 		joinStr = ""
 	)
 	if len(table) > 0 {
 		if isSubQuery(table[0]) {
-			joinStr = "(" + table[0] + ")"
+			joinStr = gstr.Trim(table[0])
+			if joinStr[0] != '(' {
+				joinStr = "(" + joinStr + ")"
+			}
 		} else {
 			joinStr = m.db.QuotePrefixTableName(table[0])
 		}
 	}
 	if len(table) > 2 {
 		model.tables += fmt.Sprintf(
-			" INNER JOIN %s AS %s ON (%s)",
-			joinStr, m.db.QuoteWord(table[1]), table[2],
+			" %s JOIN %s AS %s ON (%s)",
+			operator, joinStr, m.db.QuoteWord(table[1]), table[2],
 		)
 	} else if len(table) == 2 {
 		model.tables += fmt.Sprintf(
-			" INNER JOIN %s ON (%s)",
-			joinStr, table[1],
+			" %s JOIN %s ON (%s)",
+			operator, joinStr, table[1],
 		)
 	} else if len(table) == 1 {
 		model.tables += fmt.Sprintf(
-			" INNER JOIN %s",
-			joinStr,
+			" %s JOIN %s", operator, joinStr,
 		)
 	}
 	return model