Fix typo

en/05.1.md

@@ -12,7 +12,7 @@ Let's take a look at the corresponding mymysql and sqlite3 driver code:
 	func init() {
 	    sql.Register("sqlite3", &SQLiteDriver{})
 	}
-	
+
 	//https://github.com/mikespook/mymysql driver
 	// Driver automatically registered in database/sql
 	var d = Driver{proto: "tcp", raddr: "127.0.0.1:3306"}
@@ -21,10 +21,10 @@ Let's take a look at the corresponding mymysql and sqlite3 driver code:
 	    sql.Register("mymysql", &d)
 	}
 
-We see that all third-party database drivers have implemented this function to register themselves, and Go uses a map to save user drivers inside of `databse/sql`.
+We see that all third-party database drivers have implemented this function to register themselves, and Go uses a map to save user drivers inside of `database/sql`.
 
 	var drivers = make(map[string]driver.Driver)
-	
+
 	drivers[name] = driver
 
 Therefore, this register function can register drivers as many as you want with different names.
@@ -40,8 +40,8 @@ Here the underscore (also known as a 'blank') `_` can be quite confusing for man
 
 ## driver.Driver
 
-`Driver` is an interface containing an `Open(name string)` method that returns a `Conn` interface. 
-	
+`Driver` is an interface containing an `Open(name string)` method that returns a `Conn` interface.
+
 	type Driver interface {
 	    Open(name string) (Conn, error)
 	}
@@ -137,9 +137,9 @@ This is the interface for the result of a query operation.
 This is an alias of int64, but it implements the Result interface.
 
 	type RowsAffected int64
-	
+
 	func (RowsAffected) LastInsertId() (int64, error)
-	
+
 	func (v RowsAffected) RowsAffected() (int64, error)
 
 ## driver.Value
@@ -193,7 +193,7 @@ databse/sql defines even more high-level methods on top of database/sql/driver f
 	    mu       sync.Mutex // protects freeConn and closed
 	    freeConn []driver.Conn
 	    closed   bool
-	}	
+	}
 
 As you can see, the `Open` function returns a DB that has a freeConn, and this is a simple connection pool. Its implementation is very simple and ugly. It uses `defer db.putConn(ci, err)` in the Db.prepare function to put a connection into the connection pool. Everytime you call the Conn function, it checks the length of freeCoon. If it's greater than 0, that means there is a reusable connection and it directly returns to you. Otherwise it creates a new connection and returns.