Filters

Example

The following example performs a range query for primary key values within the range of [row1, row3). It then applies a filter to return only rows where the value of the col1 attribute column is val1.

var params = {
    tableName: 'test_table',
    // Set the start primary key for the query.
    inclusiveStartPrimaryKey: [{ 'id': 'row1' }],
    // Set the end primary key for the query (exclusive).
    exclusiveEndPrimaryKey: [{ 'id': 'row3' }]
};
// Construct a filter with the condition: col1 == "val1".
var singleColumnCondition = new TableStore.SingleColumnCondition('col1', 'val1', TableStore.ComparatorType.EQUAL);
params.columnFilter = singleColumnCondition;

// Call the getRange method to query data.
client.getRange(params, function (err, data) {
    if (err) {
        console.log('Range get failed with error: ', err);
        return;
    }

    // Process the response.
    console.log('* RequestId: ', data.RequestId);
    console.log('* Read CU Cost: ', data.consumed.capacityUnit.read);
    console.log('* Write CU Cost: ', data.consumed.capacityUnit.write);
    console.log('* Rows Data: ');
    data.rows.forEach(function (row) {
         console.log(row);
    });
});

• To exclude rows that do not contain the specified attribute column, set passIfMissing to false.

  singleColumnCondition.passIfMissing = false;

• To evaluate all data versions, set latestVersionOnly to false. If any data version meets the condition, the row is returned.

  singleColumnCondition.latestVersionOnly = false

Example

The following example performs a range query for rows with primary key values in the range of [row1, row3) and then applies a composite filter.

var params = {
    tableName: 'test_table',
    // Set the start primary key.
    inclusiveStartPrimaryKey: [{ 'id': 'row1' }],
    // Set the end primary key (exclusive).
    exclusiveEndPrimaryKey: [{ 'id': 'row3' }]
};

// Construct the first single column condition: col1 == "val1".
var singleColumnCondition1 = new TableStore.SingleColumnCondition('col1', 'val1', TableStore.ComparatorType.EQUAL);
// Construct the second single column condition: col2 == "val2".
var singleColumnCondition2 = new TableStore.SingleColumnCondition('col2', 'val2', TableStore.ComparatorType.EQUAL);
// Construct the first composite condition: col1 == "val1" OR col2 == "val2".
var compositeCondition1 = new TableStore.CompositeCondition(TableStore.LogicalOperator.OR);
compositeCondition1.addSubCondition(singleColumnCondition1);
compositeCondition1.addSubCondition(singleColumnCondition2);
// Construct the third single column condition: col3 == "val3".
var singleColumnCondition3 = new TableStore.SingleColumnCondition('col3', 'val3', TableStore.ComparatorType.EQUAL);
// Construct the second composite condition: (col1 == "val1" OR col2 == "val2") AND col3 == "val3".
var compositeCondition2 = new TableStore.CompositeCondition(TableStore.LogicalOperator.AND);
compositeCondition2.addSubCondition(compositeCondition1);
compositeCondition2.addSubCondition(singleColumnCondition3);
// Add the filter to the query.
params.columnFilter = compositeCondition2

// Call the getRange method to query data.
client.getRange(params, function (err, data) {
    if (err) {
        console.log('Range get failed with error: ', err);
        return;
    }

    // Process the response.
    console.log('* RequestId: ', data.RequestId);
    console.log('* Read CU Cost: ', data.consumed.capacityUnit.read);
    console.log('* Write CU Cost: ', data.consumed.capacityUnit.write);
    console.log('* Rows Data: ');
    data.rows.forEach(function (row) {
         console.log(row);
    });
});