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MySqlDataAdapter Update table that uses Inner Join

I'm tring to add the Insert, Update and Delete commands to a MySqlDataAdapter which has the data added to it with the command:
//iec211.4521studenti
string lv_sObsTable = "`" + mv_sDatabase + "`.`" + mv_sGroup + "observatii`";
string lv_sStudTable = "`" + mv_sDatabase + "`.`" + mv_sGroup + "studenti'";
string lv_sObservatiiCommand = "SELECT o.idObservatie, o.idStudent, s.nume, o.observatie, o.lastUpdate FROM " + lv_sObsTable + " o INNER JOIN " + lv_sStudTable + " s USING (idStudent) ORDER BY s.nume ASC";
mv_dtAdapterObservatii = new MySqlDataAdapter(lv_sObservatiiCommand, mv_sqlConnection);
mv_dtAdapterObservatii.Fill(mv_dsTables, lv_sCurrentTable);
I've serched for an answer and I've found two possible solutions for UPDATE, but both of them give me an error:
string lv_sObsTB = "`" + mv_sDatabase + "`.`" + mv_sGroup + "observatii`";
string lv_sStudTB = "`" + mv_sDatabase + "`.`" + mv_sGroup + "studenti`";
//VERSION 1
string lv_sCommand = "UPDATE o SET s.idStudent=#idStudent, o.observatie=#observatie FROM " + lv_sObsTB + " AS o INNER JOIN " + lv_sStudTB + " s ON o.idStudent=s.idStudent ";
MySqlCommand lv_sqlCommand = new MySqlCommand(lv_sCommand);
lv_sqlCommand.Parameters.Add("#idStudent", MySqlDbType.Int16, 10, "idStudent");
lv_sqlCommand.Parameters.Add("#observatie", MySqlDbType.VarChar, 255, "observatie");
mv_dtAdapterObservatii.UpdateCommand = lv_sqlCommand;
//VERSION 2
string lv_sCommand = "UPDATE " + lv_sObsTB + " SET " + "idStudent=#" + lv_sStudTB + ".idStudent, observatie=#observatie WHERE idObservatie=#idObservatie AND " + lv_sObsTB + ".idStudent IN (SELECT " + lv_sStudTB + ".idStudent FROM " + lv_sStudTB + ")";
MySqlCommand lv_sqlCommand = new MySqlCommand(lv_sCommand);
lv_sqlCommand.Parameters.Add("#" + lv_sStudTB + ".idStudent", MySqlDbType.Int16, 10, "idStudent");
lv_sqlCommand.Parameters.Add("#observatie", MySqlDbType.VarChar, 255, "observatie");
lv_sqlCommand.Parameters.Add("#idObservatie", MySqlDbType.Int16, 10, "idObservatie");
mv_dtAdapterObservatii.UpdateCommand = lv_sqlCommand;
The error message for the first version is : "You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'FROM iec211.4521observatii ASS o INNER JOIN iec211.4521studenti s ON o.id' at line 1"
The error message for the second version is:You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '.4521studenti'.idStudenti, observatie='test' WHERE idObservatie=1 ANDiec211.' at line 1"
I don't know how to use the MySQL commands in combination with MySqlCommand and MySqlDataAdapter.
Until now I've used the following command to obtain data for my table:
string lv_sObservatiiCommand = "SELECT * FROM `" + mv_sDatabase + "`.`" + mv_sGroup + "observatii` ORDER BY idStudent ASC";
mv_dtAdapterObservatii = new MySqlDataAdapter(lv_sObservatiiCommand, mv_sqlConnection);
mv_dtAdapterObservatii.Fill(mv_dsTables, lv_sCurrentTable);
In combination with MySqlCommandBuilder to get the update command and the parameters that needed to be setted:
lv_sqlCommandBuilder = new MySqlCommandBuilder(mv_dtAdapterObservatii);
mv_dtAdapterObservatii.UpdateCommand = lv_sqlCommandBuilder.GetUpdateCommand();
Can someone please explain to me how to correctly add the insert, update and delete commands to a MySqlDataAdapter that contains an INNER JOIN between 2 tables ?
I know that each table must be in a different data adapter, and they are. The "4521studenti" table is inside "mv_dtAdapterStudenti", which is not included in the code above.
Thank you for the help and I hope this won't be considered as a bad post. :)

Okey. I think I've figured it out.
This is the SELECT command for 4521observatii:
string lv_sStudent = "`" + mv_sDatabase + "`.`" + mv_sGroup + "studenti`";
string lv_sObservatii = "`" + mv_sDatabase + "`.`" + mv_sGroup + "observatii`";
string lv_sObservatiiCommand = "SELECT o.idObservatie, o.idStudent, s.nume, o.observatie, o.lastUpdate FROM " + lv_sObservatii + " o INNER JOIN " + lv_sStudent + " s USING (idStudent) ORDER BY s.nume ASC";
// Read data from the server for the current table and add it to the DataSet
mv_dtAdapterObservatii = new MySqlDataAdapter(lv_sObservatiiCommand, mv_sqlConnection);
mv_dtAdapterObservatii.Fill(mv_dsTables, lv_sCurrentTable);
And this is the code for the UPDATE command, inside a different method:
// `iec211`.`4521observatii`
string lv_sObsTB = "`" + mv_sDatabase + "`.`" + mv_sGroup + "observatii`";
// `iec211`.`4521studenti`
string lv_sStudTB = "`" + mv_sDatabase + "`.`" + mv_sGroup + "studenti`";
string lv_sSelectStudenti = "(SELECT idStudent FROM " + lv_sStudTB + " WHERE idStudent=#idStudent)";
string lv_sCommand = "UPDATE " + lv_sObsTB + " SET idStudent="+ lv_sSelectStudenti + ", observatie=#observatie WHERE idObservatie=#idObservatie";
MySqlCommand lv_sqlCommand = new MySqlCommand(lv_sCommand);
lv_sqlCommand.Parameters.Add("#idStudent", MySqlDbType.Int16, 10, "idStudent");
lv_sqlCommand.Parameters.Add("#observatie", MySqlDbType.VarChar, 255, "observatie");
lv_sqlCommand.Parameters.Add("#idObservatie", MySqlDbType.Int16, 10, "idObservatie");
mv_dtAdapterObservatii.UpdateCommand = lv_sqlCommand;
mv_dtAdapterObservatii.UpdateCommand.Connection = mv_sqlConnection;
The idea is that when I use INNER JOIN I bring data from two different tables and put them together. When I used the UPDATE command, the program didn't know which table he was using and gived those errors.
So I thought what if I update the values of 4521observatii and for the column that is used as FOREIGN KEY I assign the value from 4521studenti.
I know it's like "Tell me your name so I can tell you your name.", but it worked for me.
I hope this will help others and you have a better and cleaner solution, pleas tell me :)

Syntax Error on a Sql Parametrized update command - c#

It's my first SQL Parametrized update command in c# and i have a syntax error when i exectued my update.
Here is my code :
string maRequete = "UPDATE " + strNomTable + " set "
+ "evetype = #evetype ,"
+ "evedes = #evedes ,"
+ "evecli = #evecli ,"
+ "eveusermo = #eveusermo ,"
+ "eveinterv = #eveinterv where eveNum = " + '"' + strEvtNumeroString.ToString() + '"';
OleDbCommand DbCommand = new OleDbCommand(maRequete);
DbCommand.Parameters.Add("#evetype", OleDbType.VarChar);
DbCommand.Parameters.Add("#evedes", OleDbType.VarChar);
DbCommand.Parameters.Add("#evecli", OleDbType.VarChar);
DbCommand.Parameters.Add("#eveusermo", OleDbType.VarChar);
DbCommand.Parameters.Add("#eveinterv", OleDbType.VarChar);
DbCommand.Parameters["#evetype"].Value = m_strEvtType.ToString().Trim();
DbCommand.Parameters["#evedes"].Value = m_strDesignation.ToString().Trim();
DbCommand.Parameters["#evecli"].Value = m_strCodeClient.ToString().Trim();
DbCommand.Parameters["#eveusermo"].Value = m_strUserModification;
DbCommand.Parameters["#eveinterv"].Value = m_strCodeIntervenant.ToString().Trim();
try
{
string strStringConnect = #"Provider=vfpoledb.1;Data Source=" + m_strDirectoryDBF + "\\" + strDbfFile + ".dbf;Collating Sequence=general";
OleDbConnection DbConnection = new OleDbConnection(strStringConnect);
DbCommand.CommandType = System.Data.CommandType.Text;
DbConnection.Open();
DbCommand.Connection = DbConnection;
DbCommand.ExecuteNonQuery();
return "O";
}
catch (Exception Ex)
{
return Ex.Message;
}
Anyone have an idea where is my mistake ? In addition, i wrote in a old DBF file (Visual Foxpro) and i think i don't have access to log in order to debug the query :(.
Thanks a lot :)
Best regards,
Nixeus

Try using single quotes in your UPDATE statement instead of double quotes. The last line
+ "eveinterv = #eveinterv where eveNum = " + '"' + strEvtNumeroString.ToString() + '"';
should be
+ "eveinterv = #eveinterv where eveNum = '" + strEvtNumeroString.ToString() + "'";

change your command text as
string maRequete = "UPDATE " + strNomTable + " set "
+ "evetype = #evetype ,"
+ "evedes = #evedes ,"
+ "evecli = #evecli ,"
+ "eveusermo = #eveusermo ,"
+ "eveinterv = #eveinterv where eveNum = '" + strEvtNumeroString.ToString() + "'";

If you print out maRequete, and try executing it interactively, you will find the SQL syntax is incorrect. It seems likely you're using double-quotes to denote string constants; in SQL you should use single quotes for that. It's possible your data contains a single quote (i.e. an apostrophe). In that case, you need to add and extra one e.g.
INSERT ... values ('you''ll need two apostrophes for this');
These are just SQL rules. You have to give the server valid syntax if it's to execute your query.

Read Data from data set

I have data set that is being filled from sql query, like this
cmd_sql.CommandText = " SELECT BrDok " +
" FROM ordersstavke " +
" WHERE SifParFil = '" + rw_mat["sifskl_kor"] + "'";
MySqlDataAdapter sql_adapter = new MySqlDataAdapter(cmd_sql);
DataSet ds_dok = new DataSet("ordersstavke");
sql_adapter.Fill(ds_dok);
Now I want to extract value from data set for sql update, like this one
myQuery = "UPDATE ordersstavke " +
"SET BrDok = '" + rw_mat["brdok"] + "', " +
"SifParFil = '" + rw_mat["sifskl_kor"] + "', " +
"WHERE BrDok = " + ds_dok.Tables["ordersstavke"].Rows[0]["BrDok"] + "'";
I tried this ds_dok.Tables["ordersstavke"].Rows[0]["BrDok"] but I got an error,
I was thinking to do something like this
string BrDok;
BrDok = ds_dok.["BrDok"].ToString();
But nothing, how to extract that BrDok or just put it into procedure?
Thanks infront!

Make it
DataSet ds_dok = new DataSet("ordersstavke");
sql_adapter.Fill(ds_dok,"BrDok");
Then use
ds_dok.Tables["BrDok"].Rows[0]["BrDok"].ToString()

Try this
ds_dok.Tables[0].Rows[0]["BrDok"]

If you provide a string argument for the dataset class, then it will be the dataset name and not the datatable name. And there is no table in the database with name you provided for a dataset, so give it while filling the dataset. Write some thing like below.
DataSet ds_dok = new DataSet();
sql_adapter.Fill(ds_dok,"ordersstavke");
and you can write all the remaining code as it is in your code part.
And your second update query has some syntax error, see it like below
myQuery = "UPDATE ordersstavke " + "SET BrDok = '" + rw_mat["brdok"] + "', "
+ "SifParFil = '" + rw_mat["sifskl_kor"] + "', " + "WHERE BrDok
= '" + ds_dok.Tables["ordersstavke"].Rows[0]["BrDok"] + "'";
You forgot to put an starting inverted comma at the where clause.

Just a small hint to the sql-command. You should use sql-parameters to prefent sql-injection.

Update/Insert into table

I have to update table on SQL Server but first i have to check for existing data in table so if data is there update it, if not make a new insert:
cmd_sql.CommandText = " SELECT BrDok as id_dok " +
" FROM ordersstavke " +
" WHERE SifParFil = '" + rw_mat["sifskl_kor"] + "'" +
" AND DokumentTip = '" + rw_mat["vrst_dok"] + "'";
MySqlDataAdapter sql_adapter = new MySqlDataAdapter(cmd_sql);
DataSet dt_dok = new DataSet("DOK_MAT_EXCHANGE");
sql_adapter.Fill(dt_dok);
if (dt_dok.Tables["DOK_MAT_EXCHANGE"].Rows.Count == 0)
{
myQuery = " INSERT INTO ordersstavke (BrDok, DocumentTip, SifParFil) " +
" VALUES ('" + rw_mat["brdok"] + "', '" +
rw_mat["vrst_dok"] + "', '" +
rw_mat["sifskl_kor"] + "')";
}
else
{
UPDATE DATA
}
But I have an error in the code, the error is here if (dt_dok.Tables["DOK_MAT_EXCHANGE"].Rows.Count == 0)
Object reference not set to an instance of an object.
The problem is in this if statement...

DOK_MAT_EXCHANGE is the name of the DataSet, not of the first table.
You should test with
if (dt_dok.Tables[0].Rows.Count == 0)
Also, I think is better to use a syntax like this to discover how many records are presents
cmd_sql.CommandText = "SELECT COUNT(BrDok) as id_dok " +
" FROM ordersstavke " +
" WHERE SifParFil = ?p1 " +
" AND DokumentTip = ?p2";
cmd_sql.Parameters.AddWithValue("?p1", rw_mat["sifskl_kor"] );
cmd_sql.Parameters.AddWithValue("?p2", rw_mat["vrst_dok"] );
int rowCount = (Int32)cmd_sql.ExecuteScalar();

change
DataSet dt_dok = new DataSet("DOK_MAT_EXCHANGE");
to
DataSet dt_dok = new DataSet("ordersstavke ");
and
if (dt_dok.Tables["DOK_MAT_EXCHANGE"].Rows.Count == 0)
to
if (dt_dok.Tables["ordersstavke "].Rows.Count == 0)

Accessing the first table via the dataset name is incorrect, that's for setting the XML.
Instead use
dt_dok.Tables[0].Rows.Count;
That being said, you're better off writing this as a single SQL statement instead of a separate select && insert. This way you're not going to the DB multiple times.
var sql = #"if exists(select * from ordersstavke where SifParFil = ? and DokumentTip = ?)
then
-- do insert statement
else
-- do update
end if";
This might also be better done with a stored proc, so you don't have as much SQL code in C#. It's easier to manage multiple operations that way.
And for crying out loud, use SqlParameters, not string concatenation! That's just asking for trouble!

Ok, thanks guys, I wrote it like this
if (ds_dok.Tables[0].Rows.Count <= 0)
{
myQuery = " INSERT INTO ordersstavke (BrDok, " +
" SifParFil) " +
" VALUES ('" + rw_mat["brdok"] + "', '" +
rw_mat["sifskl_kor"] + "')";
}
else if (ds_dok.Tables[0].Rows.Count >= 1)
{
myQuery = "UPDATE ordersstavke " +
"SET BrDok = '" + rw_mat["brdok"] + "', " +
"SifParFil = '" + rw_mat["sifskl_kor"] + "', " +
"WHERE BrDok = " + ds_dok.Tables["ordersstavke"].Rows[0]["BrDok"].ToString() + "'";
}
But there is a small problem in the section update: s_dok.Tables["ordersstavke"].Rows[0]["BrDok"].ToString(), here it give me that loving error : Object reference not set to an instance of an object.
Maybe the update on MySQL goes on different way, I'm referencing on example on sql server and there update goes differently

MySQL Returning Column Names instead of their Content

Okay, so in the past few weeks I've probably written about 40 select statements. So, I know how to do it. And I've just written another one, but this time I need to use ComboBox values to match against, and it keeps resulting in the names of the column (the right column, mind you), instead of what's inside the column.
string st = "SELECT '" + txtchange.Text + "'
FROM mysql_9269_dbase." + pages.Text + "";
MySql.Data.MySqlClient.MySqlCommand cd = new MySql.Data.MySqlClient.MySqlCommand(st, msc);
cd.CommandType = CommandType.Text;
MySql.Data.MySqlClient.MySqlDataReader msdr = cd.ExecuteReader();
while(msdr.Read())
{
txt.Text = msdr[0].ToString();
}
Now, why is it returning the column name instead of the content of that column?

Lose the single quotes.
Change
"SELECT '" + txtchange.Text + "' "
to
"SELECT " + txtchange.Text + " "

In sql you can do it like this.
string query = "Execute("+"'SELECT " + txtchange.Text + " FROM mysql_9269_dbase." + pages.Text + "')";