function db_insert(document_list) {

var insertSql = null;

for(var i = 0; i < document_list.length; i++) {

console.log(document_list[i].documentId + ',' + document_list[i].name + ',' + document_list[i].brief);

}

for(var i = 0; i < document_list.length; i++) {

if(i == 0) {

insertSql = ' select "' +document_list[i].documentId+ '","' +document_list[i].name+ '","' +(document_list[i].brief == null ? " " : document_list[i].brief)+ '" ';

} else {

insertSql += ' union all select "' + document_list[i].documentId + '","' + document_list[i].name + '","' +(document_list[i].brief == null ? " " : document_list[i].brief)+ '" ';

}

}

console.log("sql " + insertSql);

db.transaction(function(tx) {

tx.executeSql('insert into document(documentId,name,brief) ' + insertSql, [], onSuccess, onError);

});

}

语句拼写的时候中间有undefined变量会导致整体undefined