digitalmars.D.learn - mysql-native Help required

Vino (27/27) Oct 22 2020 Hi All,

novice3 (2/9) Oct 22 2020 where Connections class constructor implemented?
Steven Schveighoffer (9/41) Oct 22 2020 I'd declare this immutable, so it's not stored in the class:

Vino (27/69) Oct 22 2020 Hi Steve,

Steven Schveighoffer (15/100) Oct 22 2020 Different error:

aberba (5/22) Oct 23 2020 Was about to say that. Part of why I think some people hate

Vino (4/10) Oct 24 2020 Hi All,

Vino <akashvino79 gmail.com> writes:

Hi All,


   Request your help on the below code as it is not working as 
expected.

GetConnections.d

module common.GetConnections;
import mysql;

class Connections
{
   private Connection conn;
   auto constr = 

   this.conn = new Connection(constr);
}

GetHost.d

import common.GetConnections;
import std.array : array;
import std.variant;
import mysql;
import std.stdio: writeln;

void main()
{
  auto conn = new Connections();
  Row[] data = conn.query("SELECT * FROM hostlog").array;
  writeln(data[]);
}

From,
Vino

Oct 22 2020

novice3 <sorryno em.ail> writes:

On Thursday, 22 October 2020 at 11:04:53 UTC, Vino wrote:
 class Connections
 {
   private Connection conn;
   auto constr = 

   this.conn = new Connection(constr);
 }

where Connections class constructor implemented?

Oct 22 2020

Steven Schveighoffer <schveiguy gmail.com> writes:

On 10/22/20 7:04 AM, Vino wrote:
 Hi All,
 
 
    Request your help on the below code as it is not working as expected.
 
 GetConnections.d
 
 module common.GetConnections;
 import mysql;
 
 class Connections
 {
    private Connection conn;
    auto constr = 


I'd declare this immutable, so it's not stored in the class:

immutable constr = "...";

    this.conn = new Connection(constr);

You are trying to assign an instance member at compile time, with no 
actual instance.

You need a constructor

      this() { this.conn = new Connection(constr); }
 }
 
 GetHost.d
 
 import common.GetConnections;
 import std.array : array;
 import std.variant;
 import mysql;
 import std.stdio: writeln;
 
 void main()
 {
   auto conn = new Connections();
   Row[] data = conn.query("SELECT * FROM hostlog").array;
   writeln(data[]);
 }

The rest should work.

-Steve

Oct 22 2020

Vino <akashvino79 gmail.com> writes:

On Thursday, 22 October 2020 at 14:08:30 UTC, Steven 
Schveighoffer wrote:
 On 10/22/20 7:04 AM, Vino wrote:
 Hi All,
 
 
    Request your help on the below code as it is not working as 
 expected.
 
 GetConnections.d
 
 module common.GetConnections;
 import mysql;
 
 class Connections
 {
    private Connection conn;
    auto constr = 


 I'd declare this immutable, so it's not stored in the class:

 immutable constr = "...";

    this.conn = new Connection(constr);

 You are trying to assign an instance member at compile time, 
 with no actual instance.

 You need a constructor

      this() { this.conn = new Connection(constr); }
 }
 
 GetHost.d
 
 import common.GetConnections;
 import std.array : array;
 import std.variant;
 import mysql;
 import std.stdio: writeln;
 
 void main()
 {
   auto conn = new Connections();
   Row[] data = conn.query("SELECT * FROM hostlog").array;
   writeln(data[]);
 }

 The rest should work.

 -Steve

Hi Steve,

    Thank you very much, I tried your solution, still not working

File: GetConnections.d
module common.GetConnections;
import mysql;

class Connections
{
   private Connection conn;
   immutable constr = 

   this() { this.conn = new Connection(constr); }
}

Error:
source/common/GetHost.d(11,25): Error: none of the overloads of 
query are callable using argument types (Connections, string), 
candidates are:
/root/.dub/packages/mysql-native-3.0.0/mysql-native/source/mysql
commands.d(321,13):        mysql.commands.query(Connection conn, const(char[])
sql, ColumnSpecialization[] csa = null)
/root/.dub/packages/mysql-native-3.0.0/mysql-native/source/mysql
commands.d(334,13):        mysql.commands.query(Connection conn, const(char[])
sql, VariantN!32LU[] args)
/root/.dub/packages/mysql-native-3.0.0/mysql-native/source/mysql
commands.d(342,13):        mysql.commands.query(Connection conn, ref Prepared
prepared)
/root/.dub/packages/mysql-native-3.0.0/mysql-native/source/mysql
commands.d(357,13):        mysql.commands.query(Connection conn, ref Prepared
prepared, VariantN!32LU[] args)
/root/.dub/packages/mysql-native-3.0.0/mysql-native/source/mysql
commands.d(364,13):        mysql.commands.query(Connection conn, ref
BackwardCompatPrepared prepared)
source/common/GetParams.d(11,25):        ... (2 more, -v to show) 
...

From,
Vino.B

Oct 22 2020

Steven Schveighoffer <schveiguy gmail.com> writes:

On 10/22/20 11:00 AM, Vino wrote:
 On Thursday, 22 October 2020 at 14:08:30 UTC, Steven Schveighoffer wrote:
 On 10/22/20 7:04 AM, Vino wrote:
 Hi All,


    Request your help on the below code as it is not working as expected.

 GetConnections.d

 module common.GetConnections;
 import mysql;

 class Connections
 {
    private Connection conn;
    auto constr = 


 I'd declare this immutable, so it's not stored in the class:

 immutable constr = "...";

    this.conn = new Connection(constr);

 You are trying to assign an instance member at compile time, with no 
 actual instance.

 You need a constructor

      this() { this.conn = new Connection(constr); }
 }

 GetHost.d

 import common.GetConnections;
 import std.array : array;
 import std.variant;
 import mysql;
 import std.stdio: writeln;

 void main()
 {
   auto conn = new Connections();
   Row[] data = conn.query("SELECT * FROM hostlog").array;
   writeln(data[]);
 }

 The rest should work.

 -Steve

 
 Hi Steve,
 
     Thank you very much, I tried your solution, still not working
 
 File: GetConnections.d
 module common.GetConnections;
 import mysql;
 
 class Connections
 {
    private Connection conn;
    immutable constr = 

    this() { this.conn = new Connection(constr); }
 }
 
 Error:
 source/common/GetHost.d(11,25): Error: none of the overloads of query 
 are callable using argument types (Connections, string), candidates are:
 /root/.dub/packages/mysql-native-3.0.0/mysql-native/source/mysql
commands.d(321,13):        
 mysql.commands.query(Connection conn, const(char[]) sql, 
 ColumnSpecialization[] csa = null)
 /root/.dub/packages/mysql-native-3.0.0/mysql-native/source/mysql
commands.d(334,13):        
 mysql.commands.query(Connection conn, const(char[]) sql, VariantN!32LU[] 
 args)
 /root/.dub/packages/mysql-native-3.0.0/mysql-native/source/mysql
commands.d(342,13):        
 mysql.commands.query(Connection conn, ref Prepared prepared)
 /root/.dub/packages/mysql-native-3.0.0/mysql-native/source/mysql
commands.d(357,13):        
 mysql.commands.query(Connection conn, ref Prepared prepared, 
 VariantN!32LU[] args)
 /root/.dub/packages/mysql-native-3.0.0/mysql-native/source/mysql
commands.d(364,13):        
 mysql.commands.query(Connection conn, ref BackwardCompatPrepared prepared)
 source/common/GetParams.d(11,25):        ... (2 more, -v to show) ....
 

Different error:

  Row[] data = conn.query("SELECT * FROM hostlog").array;

This is trying to call mysql-native's UFCS query function on 
Connections, which isn't valid. You need to call it on conn.conn.

But there's no access to the private Connection conn inside the 
Connections class. I'm not sure what the class is for anyway, so it's 
hard for me to suggest a proper alternative. Are you just trying to 
encapsulate the connection string? I'd suggest instead of a whole class, 
just a factory function:

Connection getConnection()
{
    return new Connection("...");
}

-Steve

Oct 22 2020

aberba <karabutaworld gmail.com> writes:

On Thursday, 22 October 2020 at 18:43:40 UTC, Steven 
Schveighoffer wrote:
 On 10/22/20 11:00 AM, Vino wrote:
 [...]

 Different error:

  Row[] data = conn.query("SELECT * FROM hostlog").array;

 This is trying to call mysql-native's UFCS query function on 
 Connections, which isn't valid. You need to call it on 
 conn.conn.

 But there's no access to the private Connection conn inside the 
 Connections class. I'm not sure what the class is for anyway, 
 so it's hard for me to suggest a proper alternative. Are you 
 just trying to encapsulate the connection string? I'd suggest 
 instead of a whole class, just a factory function:

 Connection getConnection()
 {
    return new Connection("...");
 }

 -Steve

Was about to say that. Part of why I think some people hate 
OOP...due to misuse.

All my MySQL projects have this getConnection() function.

Oct 23 2020

Vino <akashvino79 gmail.com> writes:

On Friday, 23 October 2020 at 20:28:40 UTC, aberba wrote:
 On Thursday, 22 October 2020 at 18:43:40 UTC, Steven 
 Schveighoffer wrote:
 [...]

 Was about to say that. Part of why I think some people hate 
 OOP...due to misuse.

 All my MySQL projects have this getConnection() function.

Hi All,

   Thank you very much, it resolved my issues.

Vino.B

Oct 24 2020

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