CSQL Interpreter¶

Introduction to the CSQL Interpreter¶

A Tool for SQL

The CSQL Interpreter is an application installed with CUBRID that allows you to execute in an interactive or batch mode and viewing query results. The CSQL Interpreter has a command-line interface. With this, you can store SQL statements together with their results to a file for a later use.

The CSQL Interpreter provides the best and easiest way to use CUBRID. You can develop database applications with various APIs (e.g. JDBC, ODBC, PHP, CCI, etc.; you can use the CUBRID Manager, which is a management and query tool provided by CUBRID. With the CSQL Interpreter, users can create and retrieve data in a terminal-based environment.

The CSQL Interpreter directly connects to a CUBRID database and executes various tasks using SQL statements. Using the CSQL Interpreter, you can:

• Retrieve, update and delete data in a database by using SQL statements
• Execute external shell commands
• Store or display query results
• Create and execute SQL script files
• Select table schema
• Retrieve or modify parameters of the database server system
• Retrieve database information (e.g. schema, triggers, queued triggers, workspaces, locks, and statistics)

A Tool for DBA

A database administrator(DBA) performs administrative tasks by using various administrative utilities provided by CUBRID; a terminal-based interface of CSQL Interpreter is an environment where DBA executes administrative tasks.

It is also possible to run the CSQL Interpreter in standalone mode. In this mode, the CSQL Interpreter directly accesses database files and executes commands including server process properties. That is, SQL statements can be executed to a database without running a separate database server process. The CSQL Interpreter is a powerful tool that allows you to use the database only with a csql utility, without any other applications such as the database server or the brokers.

Executing CSQL¶

csql -u dba --sysadm demodb

csql [options] database_name

csql [options] database_name@remote_host_name

csql -C demodb@192.168.1.3

$ csql
A database-name is missing.
interactive SQL utility, version 9.1
usage: csql [OPTION] database-name[@host]

valid options:
  -S, --SA-mode                standalone mode execution
  -C, --CS-mode                client-server mode execution
  -u, --user=ARG               alternate user name
  -p, --password=ARG           password string, give "" for none
  -e, --error-continue         don't exit on statement error
  -i, --input-file=ARG         input-file-name
  -o, --output-file=ARG        output-file-name
  -s, --single-line            single line oriented execution
  -c, --command=ARG            CSQL-commands
  -l, --line-output            display each value in a line
  -r, --read-only              read-only mode
  -t, --plain-output           display results in a script-friendly format (only works with -c and -i)
  -N, --skip-column-names      do not display column names in results (only works with -c and -i)
      --string-width           display each column which is a string type in this width
      --no-auto-commit         disable auto commit mode execution
      --no-pager               do not use pager
      --no-single-line         turn off single line oriented execution
      --no-trigger-action      disable trigger action

For additional information, see http://www.cubrid.org

Session Commands¶

In addition to SQL statements, CSQL Interpreter provides special commands allowing you to control the Interpreter. These commands are called session commands. All the session commands must start with a semicolon (;).

Enter the ;help command to display a list of the session commands available in the CSQL Interpreter. Note that only the uppercase letters of each session command are required to make the CSQL Interpreter to recognize it. Session commands are not case-sensitive.

"Query buffer" is a buffer to store the query before running it. If you run CSQL as giving the --no-single-line option, the query string is kept on the buffer until running ;xr command.

Reading SQL statements from a file (;REAd)

The ;REAd command reads the contents of a file into the buffer. This command is used to execute SQL commands stored in the specified file. To view the contents of the file loaded into the buffer, use the ;List command.

csql> ;read nation.sql
The file has been read into the command buffer.
csql> ;list
insert into "sport_event" ("event_code", "event_name", "gender_type", "num_player") values
(20001, 'Archery Individual', 'M', 1);
insert into "sport_event" ("event_code", "event_name", "gender_type", "num_player") values
20002, 'Archery Individual', 'W', 1);
....

Storing SQL statements into a file (;Write)

The ;Write command stores the contents of the query buffer into a file. This command is used to store queries that you entered or modified in the CSQL Interpreter.

csql> ;write outfile
Command buffer has been saved.

Appending to a file (;APpend)

This command appends the contents of the current query buffer to an outfile file.

csql> ;append outfile
Command buffer has been saved.

Executing a shell command (;SHELL)

The ;SHELL session command calls an external shell. Starts a new shell in the environment where the CSQL Interpreter is running. It returns to the CSQL Interpreter when the shell terminates. If the shell command to execute with the ;SHELL_Cmd command has been specified, it starts the shell, executes the specified command, and returns to the CSQL Interpreter.

csql> ;shell
% ls -al
total 2088
drwxr-xr-x 16 DBA cubrid   4096 Jul 29 16:51 .
drwxr-xr-x  6 DBA cubrid   4096 Jul 29 16:17 ..
drwxr-xr-x  2 DBA cubrid   4096 Jul 29 02:49 audit
drwxr-xr-x  2 DBA cubrid   4096 Jul 29 16:17 bin
drwxr-xr-x  2 DBA cubrid   4096 Jul 29 16:17 conf
drwxr-xr-x  4 DBA cubrid   4096 Jul 29 16:14 cubridmanager
% exit
csql>

Registering a shell command (;SHELL_Cmd)

The ;SHELL_Cmd command registers a shell command to execute with the SHELL session command. As shown in the example below, enter the ;shell command to execute the registered command.

csql> ;shell_c ls -la
csql> ;shell
total 2088
drwxr-xr-x 16 DBA cubrid   4096 Jul 29 16:51 .
drwxr-xr-x  6 DBA cubrid   4096 Jul 29 16:17 ..
drwxr-xr-x  2 DBA cubrid   4096 Jul 29 02:49 audit
drwxr-xr-x  2 DBA cubrid   4096 Jul 29 16:17 bin
drwxr-xr-x  2 DBA cubrid   4096 Jul 29 16:17 conf
drwxr-xr-x  4 DBA cubrid   4096 Jul 29 16:14 cubridmanager
csql>

Registering a pager command (;PAger_cmd)

The ;PAger_cmd command registers a pager command to display the query result. The way of displaying is decided by the registered command. The default is more. Also cat and less can be used. But ;Pager_cmd command works well only on Linux.

When you register pager command as more, the query result shows by page and wait until you press the space key.

csql>;pager more

When you register pager command as cat, the query result shows all in one display without paging.

csql>;pager cat

When you redirect the output with a file, the total query result will be written on the file.

csql>;pager cat > output.txt

If you register pager command as less, you can forward, backward the query result. Also pattern matching on the query result is possible.

csql>;pager less

The keyboard commands used on the less are as follows.

• Page UP, b: go up to one page. (backwording)
• Page Down, Space: go down to one page (forwarding)
• /string: find a sting on the query results
• n: find the next string
• N: find the previous string
• q: quit the paging mode.

Changing the current working directory (;CD)

This command changes the current working directory where the CSQL Interpreter is running to the specified directory. If you don't specify the path, the directory will be changed to the home directory.

csql> ;cd /home1/DBA/CUBRID
Current directory changed to  /home1/DBA/CUBRID.

Exiting the CSQL Interpreter (;EXit)

This command exits the CSQL Interpreter.

csql> ;ex

Clearing the query buffer (;CLear)

The ;CLear session command clears the contents of the query buffer.

csql> ;clear
csql> ;list

Displaying the contents of the query buffer (;List)

The ;List session command lists the contents of the query buffer that have been entered or modified. The query buffer can be modified by ;READ or ;Edit command.

csql> ;list

Executing SQL statements (;RUn)

This command executes SQL statements in the query buffer. Unlike the ;Xrun session command described below, the buffer will not be cleared even after the query execution.

csql> ;run

Clearing the query buffer after executing the SQL statement (;Xrun)

This command executes SQL statements in the query buffer. The buffer will be cleared after the query execution.

csql> ;xrun

Committing transaction (;COmmit)

This command commits the current transaction. You must enter a commit command explicitly if it is not in auto-commit mode. In auto-commit mode, transactions are automatically committed whenever SQL is executed.

csql> ;commit
Execute OK. (0.000192 sec)

Rolling back transaction (;ROllback)

This command rolls back the current transaction. Like a commit command (;COmmit), it must enter a rollback command explicitly if it is not in auto-commit mode (OFF).

csql> ;rollback
Execute OK. (0.000166 sec)

Setting the auto-commit mode (;AUtocommit)

This command sets auto-commit mode to ON or OFF. If any value is not specified, current configured value is applied by default. The default value is ON.

csql> ;autocommit off
AUTOCOMMIT IS OFF

CHeckpoint Execution (;CHeckpoint)

This command executes the checkpoint within the CSQL session. This command can only be executed when a DBA group member, who is specified for the custom option (-u user_name), connects to the CSQL Interpreter in system administrator mode (--sysadm).

Checkpoint is an operation of flushing all dirty pages within the current data buffer to disks. You can also change the checkpoint interval using a command (;set parameter_name value) to set the parameter values in the CSQL session. You can see the examples of the parameter related to the checkpoint execution interval (checkpoint_interval and checkpoint_every_size). For more information, see Logging-Related Parameters.

sysadm> ;checkpoint
Checkpoint has been issued.

Transaction Monitoring Or Termination (;Killtran)

This command checks the transaction status information or terminates a specific transaction in the CSQL session. This command prints out the status information of all transactions on the screen if a parameter is omitted it terminates the transaction if a specific transaction ID is specified for the parameter. It can only be executed when a DBA group member, who is specified for the custom option (-u user_name), connects to the CSQL Interpreter in system administrator mode (--sysadm).

sysadm> ;killtran
Tran index      User name      Host name      Process id      Program name
-------------------------------------------------------------------------------
      1(+)            dba      myhost             664           cub_cas
      2(+)            dba      myhost            6700              csql
      3(+)            dba      myhost            2188           cub_cas
      4(+)            dba      myhost             696              csql
      5(+)         public      myhost            6944              csql

sysadm> ;killtran 3
The specified transaction has been killed.

Restarting database (;REStart)

A command that tries to reconnect to the target database in a CSQL session. Note that when you execute the CSQL Interpreter in CS (client/server) mode, it will be disconnected from the server. When the connection to the server is lost due to a HA failure and failover to another server occurs, this command is particularly useful in connecting to the switched server while maintaining the current session.

csql> ;restart
The database has been restarted.

Displaying the current date (;DATE)

The ;DATE command displays the current date and time in the CSQL Interpreter.

csql> ;date
     Tue July 29 18:58:12 KST 2008

Displaying the database information (;DATAbase)

This command displays the database name and host name where the CSQL Interpreter is working. If the database is running, the HA mode (one of those following: active, standby, or maintenance) will be displayed as well.

csql> ;database
     demodb@cubridhost (active)

Displaying schema information of a class (;SChema)

The ;SChema session command displays schema information of the specified table. The information includes the table name, its column name and constraints.

csql> ;schema event
=== <Help: Schema of a Class> ===
 <Class Name>
     event
 <Attributes>
     code           INTEGER NOT NULL
     sports         CHARACTER VARYING(50)
     name           CHARACTER VARYING(50)
     gender         CHARACTER(1)
     players        INTEGER
 <Constraints>
     PRIMARY KEY pk_event_event_code ON event (code)

Displaying the trigger (;TRigger)

This command searches and displays the trigger specified. If there is no trigger name specified, all the triggers defined will be displayed.

csql> ;trigger
=== <Help: All Triggers> ===
    trig_delete_contents

Checking the parameter value(;Get)

You can check the parameter value currently set in the CSQL Interpreter using the ;Get session command. An error occurs if the parameter name specified is incorrect.

csql> ;get isolation_level
=== Get Param Input ===
isolation_level=4

Setting the parameter value (;SEt)

You can use the ;Set session command to set a specific parameter value. Note that changeable parameter values are only can be changed. To change the server parameter values, you must have DBA authorization. For information on list of changeable parameters, see Broker Configuration.

csql> ;set block_ddl_statement=1
=== Set Param Input ===
block_ddl_statement=1

-- Dynamically change the log_max_archives value in the csql accessed by dba account
csql> ;set log_max_archives=5

Setting the output width of string (;STring-width)

You can use the ;STring-width command to set the output width of character string or BIT string.

;string-width session command without a length shows the current setting length. When it is set to 0, the columns will be displayed as it is. If it sets greater than 0, the string typed columns will be displayed with the specified length.

csql> SELECT name FROM NATION WHERE NAME LIKE 'Ar%';
  'Arab Republic of Egypt'
  'Aruba'
  'Armenia'
  'Argentina'

csql> ;string-width 5
csql>  SELECT name FROM NATION WHERE NAME LIKE 'Ar%';
  'Arab '
  'Aruba'
  'Armen'
  'Argen'

csql> ;string-width
STRING-WIDTH : 5

Setting the output width of the column (;COLumn-width)

You can use the ;COLumn-width command to set the output width regardless of its data types. If you don't give a value after ;COL command, it shows the current setting length. When it sets to 0, the columns will be displayed as it is. If it sets to greater than 0, the columns will be displayed with the specified length.

csql> CREATE TABLE tbl(a BIGINT, b BIGINT);
csql> INSERT INTO tbl VALUES(12345678890, 1234567890)
csql> ;column-width a=5
csql> SELECT * FROM tbl;
      12345            1234567890
csql> ;column-width
COLUMN-WIDTH a : 5

Setting the view level of executing query plan (;PLan)

You can use the ;PLan session command to set the view level of executing query plan the level is composed of simple, detail, and off. Each command refers to the following:

• off: Not displaying the query execution plan
• simple: Displaying the query execution plan in simple version (OPT LEVEL=257)
• detail: Displaying the query execution plan in detailed version (OPT LEVEL=513)

Setting SQL trace(;trace)

The ;trace session command specifies if SQL trace result is printed out together with query result or not. When you set SQL trace ON by using this command, the result of query profiling is automatically shown even if you do not run "SHOW TRACE;" syntax.

For more information, see Query Profiling.

The command format is as follows.

;trace {on | off} [{text | json}]

• on: set on SQL trace.
• off: set off SQL trace.
• text: print out as a general TEXT format. If you omit OUTPUT clause, TEXT format is specified.
• json: print out as a JSON format.

Displaying information (;Info)

The ;Info session command allows you to check information such as schema, triggers, the working environment, locks and statistics.

csql> ;info lock
*** Lock Table Dump ***
 Lock Escalation at = 100000, Run Deadlock interval = 1
Transaction (index  0, unknown, unknown@unknown|-1)
Isolation COMMITTED READ
State TRAN_ACTIVE
Timeout_period -1
......

Dumping CSQL execution statistics information(;.Hist)

This command is a CSQL session command for starting to collect the statistics information in CSQL. The information is collected only for the currently connected CSQL after ";.Hist on" command is entered. Following options are provided for this session command.

• on: Starts collecting statistics information for the current connection.
• off: Stops collecting statistics information of server.

This command is executable while the communication_histogram parameter in the cubrid.conf file is set to yes. You can also view this information by using the cubrid statdump utility.

After running ";.Hist on", the execution commands such as ;.dump_hist or ;.x must be entered to output the statistics information. After ;.dump_hist or ;.x, all accumulated data are dumped and initiated.

As a reference, you should use cubrid statdump utility to check all queries' statistics information of a database server.

This example shows the server statistics information for current connection. For information on dumped specific items or cubrid statdump command, see statdump.

csql> ;.hist on
csql> ;.x
Histogram of client requests:
Name                            Rcount   Sent size  Recv size , Server time
 No server requests made

 *** CLIENT EXECUTION STATISTICS ***
System CPU (sec)              =          0
User CPU (sec)                =          0
Elapsed (sec)                 =         20

 *** SERVER EXECUTION STATISTICS ***
Num_file_creates              =          0
Num_file_removes              =          0
Num_file_ioreads              =          0
Num_file_iowrites             =          0
Num_file_iosynches            =          0
Num_data_page_fetches         =         56
Num_data_page_dirties         =         14
Num_data_page_ioreads         =          0
Num_data_page_iowrites        =          0
Num_data_page_victims         =          0
Num_data_page_iowrites_for_replacement =          0
Num_log_page_ioreads          =          0
Num_log_page_iowrites         =          0
Num_log_append_records        =          0
Num_log_archives              =          0
Num_log_checkpoints           =          0
Num_log_wals                  =          0
Num_page_locks_acquired       =          2
Num_object_locks_acquired     =          2
Num_page_locks_converted      =          0
Num_object_locks_converted    =          0
Num_page_locks_re-requested   =          0
Num_object_locks_re-requested =          1
Num_page_locks_waits          =          0
Num_object_locks_waits        =          0
Num_tran_commits              =          1
Num_tran_rollbacks            =          0
Num_tran_savepoints           =          0
Num_tran_start_topops         =          3
Num_tran_end_topops           =          3
Num_tran_interrupts           =          0
Num_btree_inserts             =          0
Num_btree_deletes             =          0
Num_btree_updates             =          0
Num_btree_covered             =          0
Num_btree_noncovered          =          0
Num_btree_resumes             =          0
Num_query_selects             =          1
Num_query_inserts             =          0
Num_query_deletes             =          0
Num_query_updates             =          0
Num_query_sscans              =          1
Num_query_iscans              =          0
Num_query_lscans              =          0
Num_query_setscans            =          0
Num_query_methscans           =          0
Num_query_nljoins             =          0
Num_query_mjoins              =          0
Num_query_objfetches          =          0
Num_network_requests          =          8
Num_adaptive_flush_pages      =          0
Num_adaptive_flush_log_pages  =          0
Num_adaptive_flush_max_pages  =          0

 *** OTHER STATISTICS ***
Data_page_buffer_hit_ratio    =     100.00
csql> ;.hist off

Displaying query execution time (;TIme)

The ;TIme session command can be set to display the elapsed time to execute the query. It can be set to ON or OFF. The current setting is displayed if there is no value specified. The default value is ON.

The SELECT query includes the time of outputting the fetched records. Therefore, to check the execution time of complete output of all records in the SELECT query, use the --no-pager option while executing the CSQC interpreter.

$ csql -u dba --no-pager demodb
csql> ;time ON
csql> ;time
TIME IS ON

Displaying a column of result record in one line(;LINe-output)

If this value is set to ON, it makes the record display in several lines by column. The default value is OFF, which makes one record display in one line.

csql> ;line-output ON
csql> select * from athlete;

=== <Result of SELECT Command in Line 1> ===

<00001> code       : 10999
        name       : 'Fernandez Jesus'
        gender     : 'M'
        nation_code: 'ESP'
        event      : 'Handball'
<00002> code       : 10998
        name       : 'Fernandez Jaime'
        gender     : 'M'
        nation_code: 'AUS'
        event      : 'Rowing'
...

Displaying query history (;HISTORYList)

This command displays the list that contains previously executed commands (input) and their history numbers.

csql> ;historylist
----< 1 >----
select * from nation;
----< 2 >----
select * from athlete;

Reading input with the specified history number into the buffer (;HISTORYRead)

You can use ;HISTORYRead session command to read input with history number in the ;HISTORYList list into the command buffer. You can enter ;run or ;xrun directly because it has the same effect as when you enter SQL statements directly.

csql> ;historyread 1

Calling the default editor (;EDIT)

This command calls the specified editor. The default editor is vi on Linux Notepad on Windows environment. Use ;EDITOR_Cmd command to specify a different editor.

csql> ;edit

Specifying the editor (;EDITOR_Cmd)

This command specifies the editor to be used with ;EDIT session command. As shown in the example below, you can specify other editor (ex: emacs) which is installed in the system.

csql> ;editor_cmd emacs
csql> ;edit