Lindorm:Data query

Prerequisites

You are logged on to the cluster management system for the target instance. For instructions, see Log on to the cluster management system.

Limitations

• To ensure data security, each query can return a maximum of 100 rows.

• The ROW field corresponds to the Lindorm row key. Both ROW and qualifier are of the varbinary type. If a qualifier does not belong to a column family, you must specify a column family.

• ROW and COL are SQL reserved fields. You must enclose them in backticks () when you use them in queries. You must also enclose a qualifier in backticks when you specify a column family for it.

HBase-compatible query

The Data Query (Compatible with HBase) page lets you query a specified table and add data to it.

Query existing data

You can query existing data in SQL tables and HBase tables.

1. In the left-side navigation pane, choose Data Query > Data Query (Compatible with HBase).

2. Set the filter conditions, including namespace and Table.

3. Optional: Specify a column family, row key, start key, end key, and limit.

4. Click Query. The existing data in the target table is displayed.

Add HBase data

You can add data only to HBase tables. This feature does not support SQL tables.

1. Click Add.

2. In the Add table data dialog box, enter the following parameters:

   Parameter	Description
   Rowkey	The row key of the HBase table.
   Column Name	The column name to add. You must specify a column family in the format <column family name:column name>, for example, f:name.
   Timestamp	Only Unix timestamps are supported.
   Value	The data value. For a list of supported data types, see Basic data types.

3. Click Determine to add a row.

Edit existing data

You can edit existing data in SQL tables and HBase tables.

1. In the Operation column of the target row, click Edit.

2. In the Edit Table Data dialog box, modify the timestamp and data value.

3. Click Determine to save your changes.

SQL executor

1. In the left-side navigation pane, choose Data Query > SQL Executor.

2. From the namespace drop-down list, select a namespace. The tables in the namespace appear on the right.

3. Optional: Get a hexadecimal string. For instructions, see Get a hexadecimal string.

4. Enter an SQL statement in the editor.

5. Click Execution.

   Note

   You can also run the statement with a keyboard shortcut. On Windows, press CTRL+ENTER. On macOS, press COMMAND+RETURN.

Get hex strings

When you query a specific row in an HBase table or perform a conditional query on a varbinary field, you must use a hexadecimal string as the value. For example, to query for a row with the row key r1, the WHERE clause in your SQL statement must be WHERE ROW='7321', where 7321 is the hexadecimal string for r1. The Data Query page in the cluster management system provides a conversion tool to generate these hexadecimal strings.

1. In the left-side navigation pane, choose Data Query > SQL Executor.

2. From the namespace drop-down list, select a namespace. The tables in the namespace appear on the right.

3. Get the converted hexadecimal string.

   • Method 1: Click Execution to view the structure of the target table. Enter the target string in the Binary to hex string conversion text box. The conversion result appears at the top of the editor.

   • Method 2: Turn on the HexString switch and click Execution. The execution results show the values converted to hexadecimal strings.

4. Write an SQL statement in the editor and replace the original value with the converted hexadecimal string.

   For example, if the original query statement is SELECT * FROM task WHERE ROW = "xxxx1";, the updated statement is SELECT * FROM task WHERE ROW = "7878787831";.

5. Click Execution.