gform增加db.GetCount,tx.GetCount,model.Count数量查询方法

g/database/gdb/gdb_base.go

@@ -128,6 +128,15 @@ func (db *Db) GetValue(query string, args ...interface{}) (interface{}, error) {
     return nil, nil
 }
 
+// 数据库查询，获取查询数量
+func (db *Db) GetCount(query string, args ...interface{}) (int, error) {
+    val, err := db.GetValue(query, args ...)
+    if err != nil {
+        return 0, err
+    }
+    return gconv.Int(val), nil
+}
+
 // 数据表查询，其中tables可以是多个联表查询语句，这种查询方式较复杂，建议使用链式操作
 func (db *Db) Select(tables, fields string, condition interface{}, groupBy, orderBy string, first, limit int, args ... interface{}) (List, error) {
     s := fmt.Sprintf("SELECT %s FROM %s ", fields, tables)

g/database/gdb/gdb_model.go

@@ -251,26 +251,10 @@ func (md *Model) Batch(batch int) *Model {
 
 // 链式操作，select
 func (md *Model) Select() (List, error) {
-    if md.fields == "" {
-        md.fields = "*"
-    }
-    s := fmt.Sprintf("SELECT %s FROM %s", md.fields, md.tables)
-    if md.where != "" {
-        s += " WHERE " + md.where
-    }
-    if md.groupBy != "" {
-        s += " GROUP BY " + md.groupBy
-    }
-    if md.orderBy != "" {
-        s += " ORDER BY " + md.orderBy
-    }
-    if md.limit != 0 {
-        s += fmt.Sprintf(" LIMIT %d, %d", md.start, md.limit)
-    }
     if md.tx == nil {
-        return md.db.GetAll(s, md.whereArgs...)
+        return md.db.GetAll(md.getFormattedSql(), md.whereArgs...)
     } else {
-        return md.tx.GetAll(s, md.whereArgs...)
+        return md.tx.GetAll(md.getFormattedSql(), md.whereArgs...)
     }
 }
 
@@ -303,3 +287,40 @@ func (md *Model) Value() (interface{}, error) {
     return "", nil
 }
 
+// 链式操作，查询数量，fields可以为空，也可以自定义查询字段，
+// 当给定自定义查询字段时，该字段必须为数量结果，否则会引起歧义，如：Fields("COUNT(id)")
+func (md *Model) Count() (int, error) {
+    if md.fields == "" || md.fields == "*" {
+        md.fields = "COUNT(1)"
+    }
+    s := md.getFormattedSql()
+    if len(md.groupBy) > 0 {
+        s = fmt.Sprintf("SELECT COUNT(1) FROM (%s) count_alias", s)
+    }
+    if md.tx == nil {
+        return md.db.GetCount(s, md.whereArgs...)
+    } else {
+        return md.tx.GetCount(s, md.whereArgs...)
+    }
+}
+
+// 格式化当前输入参数，返回可执行的SQL语句（不带参数）
+func (md *Model) getFormattedSql() string {
+    if md.fields == "" {
+        md.fields = "*"
+    }
+    s := fmt.Sprintf("SELECT %s FROM %s", md.fields, md.tables)
+    if md.where != "" {
+        s += " WHERE " + md.where
+    }
+    if md.groupBy != "" {
+        s += " GROUP BY " + md.groupBy
+    }
+    if md.orderBy != "" {
+        s += " ORDER BY " + md.orderBy
+    }
+    if md.limit != 0 {
+        s += fmt.Sprintf(" LIMIT %d, %d", md.start, md.limit)
+    }
+    return s
+}

g/database/gdb/gdb_transaction.go

@@ -13,6 +13,7 @@ import (
     "database/sql"
     _ "github.com/lib/pq"
     _ "github.com/go-sql-driver/mysql"
+    "gitee.com/johng/gf/g/util/gconv"
 )
 
 // 数据库事务对象
@@ -122,6 +123,15 @@ func (tx *Tx) GetValue(query string, args ...interface{}) (interface{}, error) {
     return nil, nil
 }
 
+// 数据库查询，获取查询数量
+func (tx *Tx) GetCount(query string, args ...interface{}) (int, error) {
+    val, err := tx.GetValue(query, args ...)
+    if err != nil {
+        return 0, err
+    }
+    return gconv.Int(val), nil
+}
+
 // (事务)sql预处理，执行完成后调用返回值sql.Stmt.Exec完成sql操作
 // 记得调用sql.Stmt.Close关闭操作对象
 func (tx *Tx) Prepare(query string) (*sql.Stmt, error) {

geg/database/mysql/mysql.go

@@ -17,7 +17,7 @@ func init () {
         Host    : "127.0.0.1",
         Port    : "3306",
         User    : "root",
-        Pass    : "123456",
+        Pass    : "8692651",
         Name    : "test",
         Type    : "mysql",
         Role    : "master",
@@ -285,6 +285,19 @@ func linkopSelect3() {
     fmt.Println()
 }
 
+// 链式查询数量1
+func linkopCount1() {
+    fmt.Println("linkopCount1:")
+    r, err := db.Table("user u").LeftJoin("user_detail ud", "u.uid=ud.uid").Where("u.uid=?", 1).Count()
+    if err == nil {
+        fmt.Println(r)
+    } else {
+        fmt.Println(err)
+    }
+    fmt.Println()
+}
+
+
 // 错误操作
 func linkopUpdate1() {
     fmt.Println("linkopUpdate1:")
@@ -462,10 +475,11 @@ func main() {
     //linkopSelect1()
     //linkopSelect2()
     //linkopSelect3()
+    linkopCount1()
     //linkopUpdate1()
     //linkopUpdate2()
     //linkopUpdate3()
-    linkopUpdate4()
+    //linkopUpdate4()
     //keepPing()
     //transaction1()
     //transaction2()