'Declaration
 
Public MustOverride Function PrepareSQLStatement( _
   ByVal sqlStmt As String, _
   ByVal cmdType As CommandType, _
   ByVal commandParams As DataParameterCollection _
) As String

public abstract string PrepareSQLStatement( 
   string sqlStmt,
   CommandType cmdType,
   DataParameterCollection commandParams
)

Parameters

sqlStmt

The statement to prepare and format

cmdType

The type of query being executed

commandParams

Parameters for the parameterized query or stored procedure

Return Value

This method will replace special tokens with statements or parameter names according to the type of query and parameters passed in. For example, the {DATE} token will be replaced with the database type's special date statement (as returned by the GetDateStatement Method). Parameters are specified using the {n} syntax where n is an ascending number. The number of {n} parameters must match the number of parameters specified in the commandParams argument.

For example, the string:

SELECT {DATE} AS CurDate FROM some_table WHERE name = {0} AND id = {1}

with the parameters named "nameVal" and "idVal" will be formatted as such with an MSSQL provider:

SELECT GETDATE() AS CurDate FROM some_table WHERE name = @nameVal AND id = @idVal

This statement can then be executed against the database using an ADO.NET IDbCommand instance, or the SqlHelper class.

NOTE: SqlHelper will automatically call this method during Execute* methods like ExecuteNonQuery or ExecuteDataSet. Generally, this method should not be called directly, only through SqlHelper.

Reference

DbProvider Class
DbProvider Members