INSERT More than 50 Query Using same opened connection - mysql

Question

So what i basically want is to insert more than 1 query to my database without needing of conn.close than conn.open too many times and also doing try more than 50 times ..
Here is exp for the code :
Dim COMMAND As MySqlCommand
Dim reader As MySqlDataReader
Dim conn As MySqlConnection
Dim Item1 As String = "INSERT INTO item_template (entry, name, display) VALUES ('1234', 'Testing', '654';"
Dim Item3 As String = "UPDATE Item_template SET entry = '123' where name like 'test32111';"
Dim Item2 As String = "INSERT INTO item_template (entry, name, display) VALUES ('123467', 'Testing332', '65478';"
Try
conn.Open()
COMMAND = New MySqlCommand(Item1, conn)
reader = COMMAND.ExecuteReader
conn.Close()
Catch ex As Exception
MessageBox.Show(ex.Message)
End Try
Try
conn.Open()
COMMAND = New MySqlCommand(Item3, conn)
reader = COMMAND.ExecuteReader
conn.Close()
Catch ex As Exception
MessageBox.Show(ex.Message)
End Try
Try
conn.Open()
COMMAND = New MySqlCommand(Item2, conn)
reader = COMMAND.ExecuteReader
conn.Close()
Catch ex As Exception
MessageBox.Show(ex.Message)
End Try

Answer 1

Without addressing other matters like parameterized/prepared queries, the simplest fix should be...
Dim COMMAND As MySqlCommand
Dim conn As MySqlConnection
Dim Item1 As String = "INSERT INTO item_template (entry, name, display) VALUES ('1234', 'Testing', '654');"
Dim Item3 As String = "UPDATE Item_template SET entry = '123' where name like 'test32111';"
Dim Item2 As String = "INSERT INTO item_template (entry, name, display) VALUES ('123467', 'Testing332', '65478');"
Try
conn.Open()
COMMAND = New MySqlCommand("", conn)
COMMAND.CommandText = Item1
COMMAND.ExecuteNonQuery
COMMAND.CommandText = Item2
COMMAND.ExecuteNonQuery
COMMAND.CommandText = Item3
COMMAND.ExecuteNonQuery
conn.Close()
Catch ex As Exception
MessageBox.Show(ex.Message)
End Try
My VB is a little rusty though, so beware of typo-level errors (I tried to add ; more than once)

Answer 2

There are some optimizations you can make. You should embed the disposable resources in a Using-Statement. The Using statement automatically closes and disposes the resources at the end. Especially the connection will be closed automatically. It does so, even if the Using-block is left prematurely because of an exception or because a Return statement terminates the method.
Keep the connection open while processing the batch.
DRY: Don't Repeat Yourself. Try to avoid code repetition make with copy paste. In the following example I create an array of SQL texts that can be processed in a loop.
SQL commands like INSERT, UPDATE, DELETE do not return a result set. Use ExecuteNonQuery instead of ExecuteReader for them.
The command can be resued by assigning it a new command text.
Dim sqlTexts = {
"INSERT INTO item_template (entry, name, display) VALUES ('1234', 'Testing', '654';",
"UPDATE Item_template SET entry = '123' where name like 'test32111';",
"INSERT INTO item_template (entry, name, display) VALUES ('12367', 'Testing332', '65478';"
}
Using _
conn As New MySqlConnection(connectionString),
command As New MySqlCommand With {
.CommandType = CommandType.Text,
.Connection = conn
}
conn.Open()
For Each sql As String In sqlTexts
Try
command.CommandText = sql
command.ExecuteNonQuery()
Catch ex As Exception
MessageBox.Show(ex.Message)
End Try
Next
End Using
Note that the Using-statement includes the command as well as we are using VB's Implicit Line Continuation feature as for the initialization of the sqlTexts array.