I'm new to working with bound variables, so I've got a small question -
I'm using an Oracle DB and ODP.NET in a .NET app, and I'm using bound variables like this
string sql = "select * from table1 where loc=:pLoc and pno=:pPno and sno=:pSno union all select * from table2 where loc=:pLoc and pno=:pPno and sno=:pSno union all
select * from table3 where loc=:pLoc and pno=:pPno and sno=:pSno";
OracleCommand _cmd = new OracleCommand(sql, DBFacade.DbConnection);
OracleParameter pLoc = new OracleParameter(":pLoc", OracleDbType.Varchar2, 3);
pLoc.Value = loc;
OracleParameter pSno = new OracleParameter(":pSno", OracleDbType.Varchar2, 10);
pLoc.Value = sno;
OracleParameter pPno = new OracleParameter(":pPno", OracleDbType.Varchar2, 18);
pLoc.Value = pno;
_cmd.Parameters.Add(pLoc);
_cmd.Parameters.Add(pSno);
_cmd.Parameters.Add(pPno);
_odaContractPrices.SelectCommand = _cmd;
I've used bound variables successfully in other sql statements (in simpler queries like "select * from table1 where column1=:param1 and column2=:param2"), but for some reason in this one it doesn't work. Can anyone explain me why ?
Thank you very much!
I'm not sure it's the source of the error but try to remove the : in the OracleParameter constructor and use
_cmd.BindByName = true;
Actually, I think that in your case, the following will suffice:
_cmd.Parameters.Add("pLoc", loc);
_cmd.Parameters.Add("pSno", sno);
_cmd.Parameters.Add("pPno ", pno);
Related
When I execute the following code the value dr.HasRows is false, and dr.Read() returns false. The same query running in SQL Developer returns 10 rows:
var allTablesSql = "select * from all_tables where table_name = 'ADDFIELDSPIPES'";
var cmd = new OracleCommand(allTablesSql, conn);
cmd.CommandType = CommandType.Text;
var dr = cmd.ExecuteReader(CommandBehavior.CloseConnection);
if (dr.Read())
{
// We have rows!
}
If I change my query to be as follows then dr.HasRows is true and dr.Read() returns true:
var allTablesSql = "select * from all_tables where table_name like '%'";
I suspect that ODP.NET somewhere and somehow queries metadata before executing the SQL string that I supply, and this metadata query somehow prevents ODP.NET from returning any rows for my query.
I'd like to do a simple INSERT-and-then-SELECT-it-query in one "run" with dapper, roughly like so:
var query = "INSERT INTO Table(Id, Value) Values(1, :value);" +
"SELECT Id, Value FROM Table WHERE Id = 1;"
Connection.Query<Item>(query, new { value = value});
This just gives me ORA-00933: SQL command not properly ended. If I run the exact same query (in "one run", with the params manually replaced) in Oracle SQL Developer, it runs fine.
If I split this in two, and do this:
var insert = "INSERT INTO Table(Id, Value) Values(1, :value);"
var select = "SELECT Id, Value FROM Table WHERE Id = 1;"
Connection.Execute(insert, new { value = value});
var item = Connection.Query<Item>(select);
...it works fine. I've tried removing the last semicolon (which seemed to be a thing in other questions), with no luck.
I've done this exact same thing with success in another project where I'm using SQL Server.
Using Dapper 1.42.
Can anyone see what's wrong here?
Try this. In Insert add "Returning into Clause" and declare output parameters.
var param = new DynamicParameters();
param.Add(name: "IinsValue", value: value, direction: ParameterDirection.Input);
param.Add(name: "Id", dbType: DbType.Int32, direction: ParameterDirection.Output);
param.Add(name: "Value", dbType: DbType.String, direction: ParameterDirection.Output);
Connection.Execute("INSERT INTO Table(Id, Value) Values(1, :value) returning Id,Values into :id, :value", param );
var Id = param.get<int>("Id");
var Val = param.get<String>("Value");
In oracle we using select * from table_name where column_name=&value in similar way how to use ampersand in JDBC?
stmt = conn.createStatement();
String sql;
sql="select emp_name from employees"+" where emp_no=?";
ResultSet rs=stmt.executeQuery(sql);
while(rs.next()){
String emp_name=rs.getString("emp_name");
System.out.println(emp_name);
}
i wrote the above code but it is not working(showing error)
Did you read the article I provided the link to?
You use the question mark ? to point out places in your query where you want to specify a parameter, and you have to use PreparedStatement. I can't test it, but it should be something like this:
// some code to obtain the Connection object
PreparedStatement stmt = null;
String yourQuery = " SELECT emp_name FROM employees WHERE emp_no = ? ";
try {
stmt = conn.prepareStatement(yourQuery);
stmt.setLong(1, 252);
ResultSet rs = stmt.executeQuery();
while(rs.next()) {
String emp_name = rs.getString("emp_name");
System.out.println(emp_name);
}
} finally {
// close the stmt etc.
}
I'd suggest using a PreparedStatement - from memory it's something like
Connection conn = getConnection();
PreparedStatement pstmnt = conn.prepareStatement("Select * from employees where emp_no =?");
pstmnt.setLong(1,emp_no);
ResultSet rs = pstmnt.executeQuery();
but the link that #Przemyslaw Kruglej high light above will almost certainly have a good example ( I haven;t read it though ... )
We are trying out the Devart Oracle adapter but are having problems with existing code that worked with the Oracle's DataAccess DLL. We get the following example error on command.ExecuteNonQuery():
ORA-01400: cannot insert NULL into
("DatabaseName"."table_name"."col3")
Here is some example code:
const string query = #"INSERT INTO table_name (table_name_id, col1, col2, col3)
VALUES(table_name_id_seq.nextval, :col1, :col2, :col3)
RETURNING table_name_id INTO :output_id";
OracleParameter outputParam = new OracleParameter(":output_id", OracleDbType.Long, ParameterDirection.Output);
OracleParameter[] parameters = new OracleParameter[]
{
outputParam,
new OracleParameter(":col1", OracleDbType.VarChar, col1, ParameterDirection.Input),
new OracleParameter(":col2", OracleDbType.VarChar, col2, ParameterDirection.Input),
new OracleParameter(":col3", OracleDbType.Long, col3, ParameterDirection.Input)
}
using (OracleCommand command = connection.CreateCommand())
{
command.CommandText = query;
command.CommandType = CommandType.Text;
command.Parameters.AddRange(parameters);
command.ExecuteNonQuery();
int outputId = Convert.ToInt32(outputParam.Value.ToString());
}
What are we doing wrong? We are trying to insert a row using a sequence for the PK, and return the PK for that row all in one query.
Also, the query runs fine if I remove the output parameter and the returning line in the query.
Thank you for your report. We have reproduced the issue and are investigating it. As a workaround, please switch to the Direct Mode: http://www.devart.com/dotconnect/oracle/docs/?directmode.html .
I'm trying to implement a simple search, using LIKE in my SQL statement:
Using cmd As New OracleCommand
cmd.Connection = conn
cmd.CommandType = CommandType.Text
cmd.CommandText = "select * from TABLE where FIELD like '%:text%'"
cmd.Parameters.AddWithValue("text", searchValue)
...
End Using
This doesn't work - what is the best way to parameterize the search value?
select * from TABLE where FIELD like ('%' || :text || '%')
update: my bad, if you are using oracle driver, see this link for help. this depends on which driver you use for db access, in case of oledb you need to do following
here is corrected code:
Using cmd As New OracleCommand
cmd.Connection = conn
cmd.CommandType = CommandType.Text
cmd.CommandText = "select * from TABLE where FIELD like ?"
cmd.Parameters.AddWithValue("#text", '%'+searchValue+'%')
...
End Using
in case of oracle driver you need to do following:
Using cmd As New OracleCommand
cmd.Connection = conn
cmd.CommandType = CommandType.Text
cmd.CommandText = "select * from TABLE where FIELD like :text"
cmd.Parameters.AddWithValue(":text", '%'+searchValue+'%')
...
End Using
In cases like this I prefer this syntax:
select * from TABLE where INSTR(FIELD, :text) > 0