Connect to SQL database inside Script Task in SSIS

you cant use the configurations from a connection manager from inside a script task like: conectionManager1.exceuteSQLStatment(...)

once you are "inside" the script task you need to access the CM like a variable:

ConnectionManager cm;
System.Data.SqlClient.SqlConnection sqlConn;
System.Data.SqlClient.SqlCommand sqlComm;

cm = Dts.Connections["conectionManager1"];

sqlConn = (System.Data.SqlClient.SqlConnection)cm.AcquireConnection(Dts.Transaction);
sqlComm = new System.Data.SqlClient.SqlCommand("your SQL Command", sqlConn);
sqlComm.ExecuteNonQuery();

cm.ReleaseConnection(sqlConn);