| Firebird Documentation Index → Firebird 2.1 Release Notes → Command-line Utilities → ISQL Query Utility |
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Work on ISQL has involved a lot of bug-fixing and the introduction of a few new, useful features.
One trick to note is that CHAR and VARCHAR types defined in character set OCTETS (alias BINARY) now display in hex format. Currently, this feature cannot be toggled off.
The following command-line switches were added:
Command line switch -b to instruct isql to bail out on error when used in non-interactive mode, returning an error code to the operating system.
When using scripts as input in the command line, it may be totally unappropriate to let isql continue executing a batch of commands after an error has happened. Therefore, the "-b[ail]" option will cause script execution to stop at the first error it detects. No further statements in the input script will be executed and isql will return an error code to the operating system.
Most cases have been covered, but if you find some error that is not recognized by isql, you should inform the project, as this is a feature in progress.
Currently there is no differentiation by error code---any non-zero return code should be interpreted as failure. Depending on other options (like -o, -m and -m2) , isql will show the error message on screen or will send it to a file.
Even if isql is executing nested scripts, it will cease all execution and will return to the operating system when it detects an error. Nested scripts happen when a script A is used as isql input but in turn A contains an INPUT command to load script B an so on. Isql doesn't check for direct or indirect recursion, thus if the programmer makes a mistake and script A loads itself or loads script B that in turn loads script A again, isql will run until it exhaust memory or an error is returned from the database, at whose point -bail if activated will stop all activity.
DML errors will be caught when being prepared or executed, depending on the type of error.
In many cases, isql will return the line number of a DML statement that fails during execution of a script. (More about error line numbers ...)
DDL errors will be caught when being prepared or executed by default, since isql uses AUTODDL ON by default. However, if AUTO DLL is OFF, the server only complains when the script does an explicit COMMIT and this may involve several SQL statements.
The feature can be enabled/disabled interactively or from a script by means of the command
SET BAIL [ON | OFF]
As is the case with other SET commands, simply using SET BAIL will toggle the state between activated and deactivated. Using SET will display the state of the switch among many others.
Even if BAIL is activated, it doesn't mean it will change isql behavior. An additional requirement should be met: the session should be non-interactive. A non-interactive session happens when the user calls isql in batch mode, giving it a script as input.
Example
isql -b -i my_fb.sql -o results.log -m -m2
However, if the user loads isql interactively and later executes a script with the input command, this is considered an interactive session even though isql knows it is executing a script.
Example
isql
Use CONNECT or CREATE DATABASE to specify a database
SQL> set bail;
SQL> input my_fb.sql;
SQL> ^Z
Whatever contents the script has, it will be executed completely, errors and all, even if the BAIL option is enabled.
This is a command-line option -M2 to send the statistics and plans to the same output file as the other output (via the -o[utput] switch).
When the user specifies that the output should be sent to a file, two possibilities have existed for years: either
at the command line, the switch -o followed by a file name is used
the command OUTput followed by a file name is used, either in a batch session or in the interactive isql shell. (In either case, simply passing the command OUTput is enough to have the output returned to the console). However, although error messages are shown in the console, they are not output to the file.
The -m command line switch was added, to meld (mix) the error messages with the normal output to wherever the output was being redirected.
This left still another case: statistics about operations (SET STATs command) and SQL plans as the server returns them. SET PLAN and SET PLANONLY commands have been treated as diagnostic messages and, as such, were always sent to the console.
What the -m2 command line switch does is to ensure that stats and plans information go to the same file the output has been redirected to.
Neither -m nor -m2 has an interactive counterpart through a SET command. They are for use only as command-line isql options.
The following commands have been added or enhanced.
(V. 2.1) Output from a SELECT in an interactive isql session can now be stopped using Ctrl-C. Note, this merely stops fetching rows from the buffer, it does not cancel the query.
(V. 2.1) The SHOW <object_type> command is meant to show user objects of that type. The SHOW SYSTEM commmand is meant to show system objects but, until now, it only showed system tables. Now it lists the predefined system UDFs incorporated into FB 2.
It may be enhanced to list system views if we create some of them in the future.
(V. 2.1) Lists all the character set/collation pairs declared in the database.
Some people consider it useful to be able to do a SELECT inside isql and have the output sent to a file, for additional processing later, especially if the number of columns makes isql display impracticable. However, isql by default prints column headers and. in this scenario, they are a nuisance.
Therefore, printing the column headers -- previously a fixed feature -- can now be enabled/disabled interactively or from a script by means of the
SET HEADing [ON | OFF]
command in the isql shell. As is the case with other SET commands, simply using SET HEAD will toggle the state between activated and deactivated.
There is no command line option to toggle headings off.
Using SET will display the state of SET HEAD, along with other switches that can be toggled on/off in the isql shell.
This SQLDA_DISPLAY command shows the input SQLDA parameters of INSERTs, UPDATEs and DELETEs. It was previously available only in DEBUG builds and has now been promoted to the public builds. It shows the information for raw SQLVARs. Each SQLVAR represents a field in the XSQLDA, the main structure used in the FB API to talk to clients transferring data into and out of the server.
The state of this option is not included in the output when you type
SET; in isql to see the current settings of most options.
The SET TRANSACTION statement has been enhanced so that, now, all TPB options are supported:
NO AUTO UNDO
IGNORE LIMBO
LOCK TIMEOUT <number>
Example
SET TRANSACTION WAIT SNAPSHOT NO AUTO UNDO LOCK TIMEOUT 10
See also the document doc/sql.extensions/README.set_transaction.txt.
ODS (On-Disk Structure) version is now returned in the SHOW DATABASE command (C. Valderrama)
In previous versions, the only reasonable way to know where a script had caused an error was using the switch -e for echoing commands, -o to send the output to a file and -m to merge the error output to the same file. This way, you could observe the commands isql executed and the errors if they exist. The script continued executing to the end. The server only gives a line number related to the single command (statement) that it's executing, for some DSQL failures. For other errors, you only know the statement caused problems.
With the addition of -b for bail as described in (1), the user is given the power to tell isql to stop executing scripts when an error happens, but you still need to echo the commands to the output file to discover which statement caused the failure.
Now, the ability to signal the script-related line number of a failure enables the user to go to the script directly and find the offending statement. When the server provides line and column information, you will be told the exact line of DML in the script that caused the problem. When the server only indicates a failure, you will be told the starting line of the statement that caused the failure, related to the whole script.
This feature works even if there are nested scripts, namely, if script SA includes script SB and SB causes a failure, the line number is related to SB. When SB is read completely, isql continues executing SA and then isql continues counting lines related to SA, since each file gets a separate line counter. A script SA includes SB when SA uses the INPUT command to load SB.
Lines are counted according to what the underlying IO layer considers separate lines. For ports using EDITLINE, a line is what readline() provides in a single call. The line length limit of 32767 bytes remains unchanged.
When unknown parameters are used, isql now shows all of the command-line parameters and their explanations instead of just a simple list of allowed switches.
opt/firebird/bin] isql -?
Unknown switch: ?
usage: isql [options] [<database>]
-a(all) extract metadata incl. legacy non-SQL tables
-b(ail) bail on errors (set bail on)
-c(ache) <num> number of cache buffers
-ch(arset) <charset> connection charset (set names)
-d(atabase) <database> database name to put in script creation
-e(cho) echo commands (set echo on)
-ex(tract) extract metadata
-i(nput) <file> input file (set input)
-m(erge) merge standard error
-m2 merge diagnostic
-n(oautocommit) no autocommit DDL (set autoddl off)
-now(arnings) do not show warnings
-o(utput) <file> output file (set output)
-pag(elength) <size> page length
-p(assword) <password> connection password
-q(uiet) do not show the message "Use CONNECT..."
-r(ole) <role> role name
-r2 <role> role (uses quoted identifier)
-sqldialect <dialect> SQL dialect (set sql dialect)
-t(erminator) <term> command terminator (set term)
-u(ser) <user> user name
-x extract metadata
-z show program and server version
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| Firebird Documentation Index → Firebird 2.1 Release Notes → Command-line Utilities → ISQL Query Utility |