diff --git a/index.js b/index.js
index 623d11f..c44e116 100644
--- a/index.js
+++ b/index.js
@@ -73,6 +73,8 @@ class Mysqli {
           }
           defer.resolve(conn)
         })
+      } else {
+        defer.resolve(conn)
       }
     })
     return new Method(defer.promise)
diff --git a/lib/method.js b/lib/method.js
index 84805f6..031c5d0 100644
--- a/lib/method.js
+++ b/lib/method.js
@@ -22,7 +22,6 @@ class Method {
           return defer.reject('SHOW databases ' + err)
         }
         defer.resolve(row.map(it => it.Database))
-        // conn.release()
       })
 
       return defer.promise
@@ -39,7 +38,6 @@ class Method {
           return defer.reject('SHOW tables ' + err)
         }
         defer.resolve(row.map(it => Object.values(it)[0]))
-        // conn.release()
       })
 
       return defer.promise
@@ -61,9 +59,7 @@ class Method {
 
       conn.query(sql, (err, result) => {
         if (err) {
-          return defer.reject(
-            `Query ${err}; \nLast exec SQL:「${this.lastSql}」`
-          )
+          return defer.reject(`Query ${err}; \nLast exec SQL:「${sql}」`)
         }
         defer.resolve(result)
       })
@@ -107,9 +103,7 @@ class Method {
 
       conn.query(sql, (err, result) => {
         if (err) {
-          return defer.reject(
-            `Filter ${err}; \nLast exec SQL:「${this.lastSql}」`
-          )
+          return defer.reject(`Filter ${err}; \nLast exec SQL:「${sql}」`)
         }
         defer.resolve(result)
       })
@@ -151,7 +145,7 @@ class Method {
 
       conn.query(sql, (err, result) => {
         if (err) {
-          return defer.reject(`Insert ${err}; Last exec SQL: ${sql}`)
+          return defer.reject(`Insert ${err}; \nLast exec SQL: ${sql}`)
         }
 
         defer.resolve(result.insertId)
@@ -166,11 +160,17 @@ class Method {
       return Promise.reject('Update Error: empty table')
     }
 
-    let sql = `UPDATE \`${table}\` SET `
+    let sql = `UPDATE ${table} SET `
 
     let fields = [] //要更新的字段
     for (let i in doc) {
-      fields.push(i + ' = ' + escape(doc[i]))
+      let val = doc[i]
+      if (typeof val === 'object' && val.$sql) {
+        val = `(${val.$sql})`
+      } else {
+        val = escape(val)
+      }
+      fields.push(i + ' = ' + val)
     }
     sql += fields.join(',')
     sql += parser.where(where)
@@ -179,7 +179,7 @@ class Method {
       const defer = Promise.defer()
       conn.query(sql, (err, res) => {
         if (err) {
-          return defer.reject(`Update ${err}; Last exec SQL: ${sql}`)
+          return defer.reject(`Update ${err}; \nLast exec SQL: ${sql}`)
         }
 
         defer.resolve(res.affectedRows)
@@ -203,7 +203,7 @@ class Method {
       const defer = Promise.defer()
       conn.query(sql, (err, res) => {
         if (err) {
-          return defer.reject(`Remove ${err}; Last exec SQL: ${sql}`)
+          return defer.reject(`Remove ${err}; \nLast exec SQL: ${sql}`)
         }
 
         defer.resolve(res.affectedRows)
diff --git a/lib/parser.js b/lib/parser.js
index 3733d95..9fbe7da 100644
--- a/lib/parser.js
+++ b/lib/parser.js
@@ -11,7 +11,7 @@ const { escape } = require('mysql')
  * @param  [array] arr [条件数组]
  */
 
-function parseWhere(arr) {
+/*function parseWhere(arr) {
   if (typeof arr === 'string' && !!arr) {
     return ' WHERE ' + arr
   } else if (Array.isArray(arr) && arr.length > 0) {
@@ -36,13 +36,82 @@ function parseWhere(arr) {
   } else {
     return ' '
   }
+}*/
+
+function getType(val) {
+  if (val === null) {
+    return String(val)
+  }
+  return Object.prototype.toString
+    .call(val)
+    .slice(8, -1)
+    .toLowerCase()
+}
+function parse$or(arr) {
+  let sql = ''
+  for (let it of arr) {
+    sql += '('
+    if (it.$and) {
+      sql += parse$and(it.$and)
+    } else {
+      sql += parse$opt(it)
+    }
+    sql += ') OR '
+  }
+  sql = sql.slice(0, -3)
+  return sql
+}
+function parse$and(arr) {
+  let sql = ''
+  for (let it of arr) {
+    sql += '('
+    if (it.$or) {
+      sql += parse$or(it.$or)
+    } else {
+      sql += parse$opt(it)
+    }
+    sql += ') AND '
+  }
+  sql = sql.slice(0, -4)
+  return sql
+}
+
+function parse$opt(opt) {
+  let sql = ''
+  for (let k in opt) {
+    let tmp = opt[k]
+    switch (getType(tmp)) {
+      case 'object':
+        if (tmp.$like) {
+          sql += ` ${k} LIKE ${escape(tmp.$like)} `
+          break
+        }
+        if (tmp.$sql) {
+          sql += ` ${k} IN ${tmp.$sql} `
+          break
+        }
+
+        if (tmp.$in) {
+          let list = tmp.$in.map(it => {
+            return escape(it)
+          })
+          sql += ` ${k} IN (${list.join(',')}) `
+          break
+        }
+      default:
+        sql += ` ${k} = ${escape(tmp)}`
+    }
+    sql += ' AND '
+  }
+  sql = sql.slice(0, -4)
+  return sql
 }
 
 const Parser = {
   leftJoin(tables) {
     let sql = ''
     for (let it of tables) {
-      sql += ` LEFT JOIN ${it[0]} ON ${it[1]} `
+      sql += ` LEFT JOIN ${it.table} ON ${it.on} `
     }
     return sql
   },
@@ -50,7 +119,7 @@ const Parser = {
   rightJoin(tables) {
     let sql = ''
     for (let it of tables) {
-      sql += ` RIGHT JOIN ${it[0]} ON ${it[1]} `
+      sql += ` RIGHT JOIN ${it.table} ON ${it.on} `
     }
     return sql
   },
@@ -58,13 +127,28 @@ const Parser = {
   join(tables) {
     let sql = ''
     for (let it of tables) {
-      sql += ` JOIN ${it[0]} ON ${it[1]} `
+      sql += ` JOIN ${it[0]} ON ${it.on} `
     }
     return sql
   },
 
-  where(where = '') {
-    return parseWhere(where)
+  where(opt) {
+    if (typeof opt === 'string') {
+      return ` WHERE ${opt} `
+    }
+    if (typeof opt === 'function') {
+      return ` WHERE ${opt()} `
+    }
+    if (typeof opt === 'object') {
+      if (opt.$and) {
+        return parse$and(opt.$and)
+      } else if (opt.$or) {
+        return parse$or(opt.$or)
+      }
+      return parse$opt(opt)
+    }
+
+    return ' '
   },
 
   select(arr = ['*']) {