Modifying Structure Tables

Contents

• Inserting or Modifying Rows

• Deleting Rows

• Other Methods

Inserting or Modifying Rows

JChem provides the chemaxon.jchem.db.TableUpdateHandler class for updating and inserting rows in structure tables. A structure table contains fixed columns (cd_...) and, optionally, additional columns that have been defined explicitly.

Java example:

    ConnectionHandler connHandler;
    int id;          // cd_id value of compound
    // Additional columns:
    String name;
    Float stock;
    String comments;
    ...
    int updateMode = isInsertion ? TableUpdateHandler.INSERT : TableUpdateHandler.UPDATE;
    TableUpdateHandler uh = new TableUpdateHandler(connHandler, updateMode,
            tableName, "name, stock, comments");
    try {
        uh.setStructure(structureSourceString);
        if (!isInsertion) {
            uh.setID(id);
        }
        uh.setValueForAdditionalColumn(1, name);
        uh.setValueForAdditionalColumn(2, stock);
        uh.setValueForAdditionalColumn(3, comments);
        uh.execute();
    } finally {
        uh.close();
    }

Deleting Rows

The deleteRows method of the TableUpdateHandler class is suggested for deleting rows from structure tables. It also increments updateCounter for the given table in JChemProperties, which is important when caching is used during structure search.

Example:

    TableUpdateHandler.deleteRows(conh, structureTableName, "WHERE cd_id>1000");

Other Methods

Other useful methods of TableUpdateHandler:

getStructureTables	Retrieves the name of all structure tables.
createStructureTable	Creates a structure table.
dropStructureTable	Removes a structure table.