Connection property has not been initialized

Connection property has not been initialized - Npgsql C#

-1

I am trying to connect to my postgres database but im getting stuck with Connection property has not been initialized.

I am using a class for open connection

 class DBConnection
 
 public static NpgsqlConnection conn = null;

 public void Connection_open()
 
 string connstring = String.Format("Host=localhost;Database=Dokument_API;Username=postgres;Password=******");
 var conn = new NpgsqlConnection(connstring);
 conn.Open();
 
 public void Connection_close()
 
 conn.Close();

In form I have this code

private void button1_Click(object sender, EventArgs e)
 
 //Open connection from class
 DBConnection NewConnection = new DBConnection();
 NewConnection.Connection_open();

 NpgsqlCommand cmd = new NpgsqlCommand("INSERT INTO anrop (exempelanrop,beskrivning,exempelsvar) VALUES ('" + exempelanrop_text.Text + "','" + beskrivning_text.Text + "','" + exempelsvar_text.Text + "')", DBConnection.conn);
 cmd.ExecuteNonQuery();
 MessageBox.Show("Uppgifter sparade");

I get stuck on cmd.ExecuteNonQuery. Why??

asked Nov 13 '18 at 15:12

Daniel Strömberg

2

DBConnection is a bug. You shouldn't have a global connection. A connection should be opened right before it's used and closed as soon as possible. Locks taken while executing queries remain until a connection is closed. This means they end up blocking other connections.

– Panagiotis Kanavos
Nov 13 '18 at 15:16

Everytime you are opening the connection, where is your connection closing also you have used var conn which will neglect the static conn

– Hassaan
Nov 13 '18 at 15:18

If you want a generic, reusable DbConnection abstraction just use the classes already provided by ADO.NET. All ADO.NET provider classes inherit from abstract classes like DbConnection, DbCommand, DbDataReader

– Panagiotis Kanavos
Nov 13 '18 at 15:18

If you worry that opening and closing a connection is costly, don't. Most ADO.NET providers implement connection pooling. When .Dispose() or .Close() is called on a connection, it's reset and put in a connection pool, ready for reuse.

– Panagiotis Kanavos
Nov 13 '18 at 15:19

add a comment |

-1

I am trying to connect to my postgres database but im getting stuck with Connection property has not been initialized.

I am using a class for open connection

 class DBConnection
 
 public static NpgsqlConnection conn = null;

 public void Connection_open()
 
 string connstring = String.Format("Host=localhost;Database=Dokument_API;Username=postgres;Password=******");
 var conn = new NpgsqlConnection(connstring);
 conn.Open();
 
 public void Connection_close()
 
 conn.Close();

In form I have this code

private void button1_Click(object sender, EventArgs e)
 
 //Open connection from class
 DBConnection NewConnection = new DBConnection();
 NewConnection.Connection_open();

 NpgsqlCommand cmd = new NpgsqlCommand("INSERT INTO anrop (exempelanrop,beskrivning,exempelsvar) VALUES ('" + exempelanrop_text.Text + "','" + beskrivning_text.Text + "','" + exempelsvar_text.Text + "')", DBConnection.conn);
 cmd.ExecuteNonQuery();
 MessageBox.Show("Uppgifter sparade");

I get stuck on cmd.ExecuteNonQuery. Why??

asked Nov 13 '18 at 15:12

Daniel Strömberg

2

DBConnection is a bug. You shouldn't have a global connection. A connection should be opened right before it's used and closed as soon as possible. Locks taken while executing queries remain until a connection is closed. This means they end up blocking other connections.

– Panagiotis Kanavos
Nov 13 '18 at 15:16

Everytime you are opening the connection, where is your connection closing also you have used var conn which will neglect the static conn

– Hassaan
Nov 13 '18 at 15:18

If you want a generic, reusable DbConnection abstraction just use the classes already provided by ADO.NET. All ADO.NET provider classes inherit from abstract classes like DbConnection, DbCommand, DbDataReader

– Panagiotis Kanavos
Nov 13 '18 at 15:18

If you worry that opening and closing a connection is costly, don't. Most ADO.NET providers implement connection pooling. When .Dispose() or .Close() is called on a connection, it's reset and put in a connection pool, ready for reuse.

– Panagiotis Kanavos
Nov 13 '18 at 15:19

add a comment |

-1

I am trying to connect to my postgres database but im getting stuck with Connection property has not been initialized.

I am using a class for open connection

 class DBConnection
 
 public static NpgsqlConnection conn = null;

 public void Connection_open()
 
 string connstring = String.Format("Host=localhost;Database=Dokument_API;Username=postgres;Password=******");
 var conn = new NpgsqlConnection(connstring);
 conn.Open();
 
 public void Connection_close()
 
 conn.Close();

In form I have this code

private void button1_Click(object sender, EventArgs e)
 
 //Open connection from class
 DBConnection NewConnection = new DBConnection();
 NewConnection.Connection_open();

 NpgsqlCommand cmd = new NpgsqlCommand("INSERT INTO anrop (exempelanrop,beskrivning,exempelsvar) VALUES ('" + exempelanrop_text.Text + "','" + beskrivning_text.Text + "','" + exempelsvar_text.Text + "')", DBConnection.conn);
 cmd.ExecuteNonQuery();
 MessageBox.Show("Uppgifter sparade");

I get stuck on cmd.ExecuteNonQuery. Why??

asked Nov 13 '18 at 15:12

Daniel Strömberg

I am trying to connect to my postgres database but im getting stuck with Connection property has not been initialized.

I am using a class for open connection

 class DBConnection
 
 public static NpgsqlConnection conn = null;

 public void Connection_open()
 
 string connstring = String.Format("Host=localhost;Database=Dokument_API;Username=postgres;Password=******");
 var conn = new NpgsqlConnection(connstring);
 conn.Open();
 
 public void Connection_close()
 
 conn.Close();

In form I have this code

private void button1_Click(object sender, EventArgs e)
 
 //Open connection from class
 DBConnection NewConnection = new DBConnection();
 NewConnection.Connection_open();

 NpgsqlCommand cmd = new NpgsqlCommand("INSERT INTO anrop (exempelanrop,beskrivning,exempelsvar) VALUES ('" + exempelanrop_text.Text + "','" + beskrivning_text.Text + "','" + exempelsvar_text.Text + "')", DBConnection.conn);
 cmd.ExecuteNonQuery();
 MessageBox.Show("Uppgifter sparade");

I get stuck on cmd.ExecuteNonQuery. Why??

c# npgsql

asked Nov 13 '18 at 15:12

Daniel Strömberg

asked Nov 13 '18 at 15:12

Daniel Strömberg

asked Nov 13 '18 at 15:12

Daniel Strömberg

asked Nov 13 '18 at 15:12

Daniel Strömberg

asked Nov 13 '18 at 15:12

Daniel Strömberg

2

DBConnection is a bug. You shouldn't have a global connection. A connection should be opened right before it's used and closed as soon as possible. Locks taken while executing queries remain until a connection is closed. This means they end up blocking other connections.

– Panagiotis Kanavos
Nov 13 '18 at 15:16

Everytime you are opening the connection, where is your connection closing also you have used var conn which will neglect the static conn

– Hassaan
Nov 13 '18 at 15:18

If you want a generic, reusable DbConnection abstraction just use the classes already provided by ADO.NET. All ADO.NET provider classes inherit from abstract classes like DbConnection, DbCommand, DbDataReader

– Panagiotis Kanavos
Nov 13 '18 at 15:18

If you worry that opening and closing a connection is costly, don't. Most ADO.NET providers implement connection pooling. When .Dispose() or .Close() is called on a connection, it's reset and put in a connection pool, ready for reuse.

– Panagiotis Kanavos
Nov 13 '18 at 15:19

add a comment |

2

DBConnection is a bug. You shouldn't have a global connection. A connection should be opened right before it's used and closed as soon as possible. Locks taken while executing queries remain until a connection is closed. This means they end up blocking other connections.

– Panagiotis Kanavos
Nov 13 '18 at 15:16

Everytime you are opening the connection, where is your connection closing also you have used var conn which will neglect the static conn

– Hassaan
Nov 13 '18 at 15:18

If you want a generic, reusable DbConnection abstraction just use the classes already provided by ADO.NET. All ADO.NET provider classes inherit from abstract classes like DbConnection, DbCommand, DbDataReader

– Panagiotis Kanavos
Nov 13 '18 at 15:18

If you worry that opening and closing a connection is costly, don't. Most ADO.NET providers implement connection pooling. When .Dispose() or .Close() is called on a connection, it's reset and put in a connection pool, ready for reuse.

– Panagiotis Kanavos
Nov 13 '18 at 15:19

DBConnection is a bug. You shouldn't have a global connection. A connection should be opened right before it's used and closed as soon as possible. Locks taken while executing queries remain until a connection is closed. This means they end up blocking other connections.

– Panagiotis Kanavos
Nov 13 '18 at 15:16

Everytime you are opening the connection, where is your connection closing also you have used var conn which will neglect the static conn

– Hassaan
Nov 13 '18 at 15:18

If you want a generic, reusable DbConnection abstraction just use the classes already provided by ADO.NET. All ADO.NET provider classes inherit from abstract classes like DbConnection, DbCommand, DbDataReader

– Panagiotis Kanavos
Nov 13 '18 at 15:18

If you worry that opening and closing a connection is costly, don't. Most ADO.NET providers implement connection pooling. When .Dispose() or .Close() is called on a connection, it's reset and put in a connection pool, ready for reuse.

– Panagiotis Kanavos
Nov 13 '18 at 15:19

add a comment |

2 Answers
2

active

oldest

votes

your method defines a local var conn instead of asigning to the one you define on class level. Omit var:

 conn = new NpgsqlConnection(connstring);

answered Nov 13 '18 at 15:15

apomene

10.9k83457

Nice catch ... did you just washed your eyes .. :)

– Rahul
Nov 13 '18 at 15:16

add a comment |

-1

Remove keyword 'var' from the following statement:

var conn = new NpgsqlConnection(connstring);

answered Nov 13 '18 at 15:20

Naresh

614

Thanks! Dont know why I put it there. Ofcourse it should be gone! Thanks a lot!

– Daniel Strömberg
Nov 13 '18 at 15:22

Please vote me if my answer makes sense!

– Naresh
Nov 13 '18 at 15:25

add a comment |

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2 Answers
2

active

oldest

votes

2 Answers
2

active

oldest

votes

your method defines a local var conn instead of asigning to the one you define on class level. Omit var:

 conn = new NpgsqlConnection(connstring);

answered Nov 13 '18 at 15:15

apomene

10.9k83457

Nice catch ... did you just washed your eyes .. :)

– Rahul
Nov 13 '18 at 15:16

add a comment |

your method defines a local var conn instead of asigning to the one you define on class level. Omit var:

 conn = new NpgsqlConnection(connstring);

answered Nov 13 '18 at 15:15

apomene

10.9k83457

Nice catch ... did you just washed your eyes .. :)

– Rahul
Nov 13 '18 at 15:16

add a comment |

your method defines a local var conn instead of asigning to the one you define on class level. Omit var:

 conn = new NpgsqlConnection(connstring);

answered Nov 13 '18 at 15:15

apomene

10.9k83457

your method defines a local var conn instead of asigning to the one you define on class level. Omit var:

 conn = new NpgsqlConnection(connstring);

answered Nov 13 '18 at 15:15

apomene

10.9k83457

answered Nov 13 '18 at 15:15

apomene

10.9k83457

answered Nov 13 '18 at 15:15

apomene

10.9k83457

answered Nov 13 '18 at 15:15

apomene

10.9k83457

Nice catch ... did you just washed your eyes .. :)

– Rahul
Nov 13 '18 at 15:16

add a comment |

Nice catch ... did you just washed your eyes .. :)

– Rahul
Nov 13 '18 at 15:16

Nice catch ... did you just washed your eyes .. :)

– Rahul
Nov 13 '18 at 15:16

add a comment |

-1

Remove keyword 'var' from the following statement:

var conn = new NpgsqlConnection(connstring);

answered Nov 13 '18 at 15:20

Naresh

614

Thanks! Dont know why I put it there. Ofcourse it should be gone! Thanks a lot!

– Daniel Strömberg
Nov 13 '18 at 15:22

Please vote me if my answer makes sense!

– Naresh
Nov 13 '18 at 15:25

add a comment |

-1

Remove keyword 'var' from the following statement:

var conn = new NpgsqlConnection(connstring);

answered Nov 13 '18 at 15:20

Naresh

614

Thanks! Dont know why I put it there. Ofcourse it should be gone! Thanks a lot!

– Daniel Strömberg
Nov 13 '18 at 15:22

Please vote me if my answer makes sense!

– Naresh
Nov 13 '18 at 15:25

add a comment |

-1

Remove keyword 'var' from the following statement:

var conn = new NpgsqlConnection(connstring);

answered Nov 13 '18 at 15:20

Naresh

614

Remove keyword 'var' from the following statement:

var conn = new NpgsqlConnection(connstring);

answered Nov 13 '18 at 15:20

Naresh

614

answered Nov 13 '18 at 15:20

Naresh

614

answered Nov 13 '18 at 15:20

Naresh

614

answered Nov 13 '18 at 15:20

Naresh

614

Thanks! Dont know why I put it there. Ofcourse it should be gone! Thanks a lot!

– Daniel Strömberg
Nov 13 '18 at 15:22

Please vote me if my answer makes sense!

– Naresh
Nov 13 '18 at 15:25

add a comment |

Thanks! Dont know why I put it there. Ofcourse it should be gone! Thanks a lot!

– Daniel Strömberg
Nov 13 '18 at 15:22

Please vote me if my answer makes sense!

– Naresh
Nov 13 '18 at 15:25

Thanks! Dont know why I put it there. Ofcourse it should be gone! Thanks a lot!

– Daniel Strömberg
Nov 13 '18 at 15:22

Please vote me if my answer makes sense!

– Naresh
Nov 13 '18 at 15:25

add a comment |

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