El error me salta en el cmd.ExecuteNonQuery();
Código
protected void ButtonTodas_Click(object sender, EventArgs e) { foreach (GridViewRow dgi in GridInscMaterias.Rows) { CheckBox myCheckBox = dgi.Cells[0].Controls[1] as CheckBox; if (myCheckBox != null) { { ViewState["idMateria"] = GridInscMaterias.DataKeys[dgi.RowIndex][0].ToString(); ViewState["idMateria1"] = GridInscMaterias.DataKeys[dgi.RowIndex][0].ToString(); ViewState["idMateria2"] = GridInscMaterias.DataKeys[dgi.RowIndex][0].ToString(); ViewState["idMateria3"] = GridInscMaterias.DataKeys[dgi.RowIndex][0].ToString(); ViewState["idMateria4"] = GridInscMaterias.DataKeys[dgi.RowIndex][0].ToString(); ViewState["idMateria5"] = GridInscMaterias.DataKeys[dgi.RowIndex][0].ToString(); ViewState["idMateria6"] = GridInscMaterias.DataKeys[dgi.RowIndex][0].ToString(); ViewState["idMateria7"] = GridInscMaterias.DataKeys[dgi.RowIndex][0].ToString(); ViewState["idMateria8"] = GridInscMaterias.DataKeys[dgi.RowIndex][0].ToString(); ViewState["idMateria9"] = GridInscMaterias.DataKeys[dgi.RowIndex][0].ToString(); { string cadenaConexion = WebConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString; cnn.Open(); string SQL = string.Empty; string SQL1 = string.Empty; string SQL2 = string.Empty; string SQL3 = string.Empty; string SQL4 = string.Empty; string SQL5 = string.Empty; string SQL6 = string.Empty; string SQL7 = string.Empty; string SQL8 = string.Empty; string SQL9 = string.Empty; SQL = ("SELECT id_cursoMateria From CursosMaterias cm Where cm.id_Curso = @idCurso AND cm.id_Materia = @idMateria"); SQL1 = ("SELECT id_cursoMateria From CursosMaterias cm Where cm.id_Curso = @idCurso AND cm.id_Materia = @idMateria1"); SQL2 = ("SELECT id_cursoMateria From CursosMaterias cm Where cm.id_Curso = @idCurso AND cm.id_Materia = @idMateria2"); SQL3 = ("SELECT id_cursoMateria From CursosMaterias cm Where cm.id_Curso = @idCurso AND cm.id_Materia = @idMateria3"); SQL4 = ("SELECT id_cursoMateria From CursosMaterias cm Where cm.id_Curso = @idCurso AND cm.id_Materia = @idMateria4"); SQL5 = ("SELECT id_cursoMateria From CursosMaterias cm Where cm.id_Curso = @idCurso AND cm.id_Materia = @idMateria5"); SQL6 = ("SELECT id_cursoMateria From CursosMaterias cm Where cm.id_Curso = @idCurso AND cm.id_Materia = @idMateria6"); SQL7 = ("SELECT id_cursoMateria From CursosMaterias cm Where cm.id_Curso = @idCurso AND cm.id_Materia = @idMateria7"); SQL8 = ("SELECT id_cursoMateria From CursosMaterias cm Where cm.id_Curso = @idCurso AND cm.id_Materia = @idMateria8"); SQL9 = ("SELECT id_cursoMateria From CursosMaterias cm Where cm.id_Curso = @idCurso AND cm.id_Materia = @idMateria9"); ViewState["idCursoMateria"] = SQL; ViewState["idCursoMateria1"] = SQL1; ViewState["idCursoMateria2"] = SQL2; ViewState["idCursoMateria3"] = SQL3; ViewState["idCursoMateria4"] = SQL4; ViewState["idCursoMateria5"] = SQL5; ViewState["idCursoMateria6"] = SQL6; ViewState["idCursoMateria7"] = SQL7; ViewState["idCursoMateria8"] = SQL8; ViewState["idCursoMateria9"] = SQL9; string sql = string.Empty; string sql1 = string.Empty; string sql2 = string.Empty; string sql3 = string.Empty; string sql4 = string.Empty; string sql5 = string.Empty; string sql6 = string.Empty; string sql7 = string.Empty; string sql8 = string.Empty; string sql9 = string.Empty; sql = @"INSERT INTO AlumMatCursos (Id_Alumno, id_cursoMateria) VALUES (@idAlumno, @idcurMat)"; sql1 = @"INSERT INTO AlumMatCursos (Id_Alumno, id_cursoMateria) VALUES (@idAlumno, @idcurMat1)"; sql2 = @"INSERT INTO AlumMatCursos (Id_Alumno, id_cursoMateria) VALUES (@idAlumno, @idcurMat2)"; sql3 = @"INSERT INTO AlumMatCursos (Id_Alumno, id_cursoMateria) VALUES (@idAlumno, @idcurMat3)"; sql4 = @"INSERT INTO AlumMatCursos (Id_Alumno, id_cursoMateria) VALUES (@idAlumno, @idcurMat4)"; sql5 = @"INSERT INTO AlumMatCursos (Id_Alumno, id_cursoMateria) VALUES (@idAlumno, @idcurMat5)"; sql6 = @"INSERT INTO AlumMatCursos (Id_Alumno, id_cursoMateria) VALUES (@idAlumno, @idcurMat6)"; sql7 = @"INSERT INTO AlumMatCursos (Id_Alumno, id_cursoMateria) VALUES (@idAlumno, @idcurMat7)"; sql8 = @"INSERT INTO AlumMatCursos (Id_Alumno, id_cursoMateria) VALUES (@idAlumno, @idcurMat8)"; sql9 = @"INSERT INTO AlumMatCursos (Id_Alumno, id_cursoMateria) VALUES (@idAlumno, @idcurMat9)"; com.Parameters.AddWithValue("@idCurso", (ViewState["idCurso"])); com.Parameters.AddWithValue("@idMateria", (ViewState["idMateria"])); com1.Parameters.AddWithValue("@idMateria1", (ViewState["idMateria1"])); com2.Parameters.AddWithValue("@idMateria2", (ViewState["idMateria2"])); com3.Parameters.AddWithValue("@idMateria3", (ViewState["idMateria3"])); com4.Parameters.AddWithValue("@idMateria4", (ViewState["idMateria4"])); com5.Parameters.AddWithValue("@idMateria5", (ViewState["idMateria5"])); com6.Parameters.AddWithValue("@idMateria6", (ViewState["idMateria6"])); com7.Parameters.AddWithValue("@idMateria7", (ViewState["idMateria7"])); com8.Parameters.AddWithValue("@idMateria8", (ViewState["idMateria8"])); com9.Parameters.AddWithValue("@idMateria9", (ViewState["idMateria9"])); cmd.Parameters.AddWithValue("@idAlumno", (ViewState["idAlumno"])); cmd.Parameters.AddWithValue("@idcurMat", (ViewState["idCursoMateria"])); cmd1.Parameters.AddWithValue("@idcurMat1", (ViewState["idCursoMateria1"])); cmd2.Parameters.AddWithValue("@idcurMat2", (ViewState["idCursoMateria2"])); cmd3.Parameters.AddWithValue("@idcurMat3", (ViewState["idCursoMateria3"])); cmd4.Parameters.AddWithValue("@idcurMat4", (ViewState["idCursoMateria4"])); cmd5.Parameters.AddWithValue("@idcurMat5", (ViewState["idCursoMateria5"])); cmd6.Parameters.AddWithValue("@idcurMat6", (ViewState["idCursoMateria6"])); cmd7.Parameters.AddWithValue("@idcurMat7", (ViewState["idCursoMateria7"])); cmd8.Parameters.AddWithValue("@idcurMat8", (ViewState["idCursoMateria8"])); cmd9.Parameters.AddWithValue("@idcurMat9", (ViewState["idCursoMateria9"])); com.ExecuteScalar(); cmd.ExecuteNonQuery(); cnn.Close();