isql

isql [options] DSN [user [password]]
isql [options] "connection_string"

DSN
    The Data Source Name defined in odbc.ini to connect to.

user
    The username for database authentication.

password
    The password for database authentication.

-v
    Enables verbose mode, displaying more information about the connection and query execution.

-q
    Enables quiet mode, suppressing header information and prompts.

-b
    Executes in batch mode, exiting after processing input without an interactive prompt.

-n
    Disables the interactive command prompt.

-d delimiter
    Specifies a custom delimiter for SQL statements in input files.

-e
    Echoes input commands to the output.

-i input_file
    Reads SQL commands from the specified file instead of standard input.

-o output_file
    Directs all output to the specified file instead of standard output.

-x script_file
    Similar to -i, but specifically for executing a script and exiting.

-s separator
    Sets the column separator for result sets.

-m max_rows
    Limits the number of rows fetched for each query result.

-c "connection_string"
    Provides the full ODBC connection string for direct connection.

-f driver_file
    Specifies the ODBC driver file to use directly.

-?
    Displays a help message with available options.

isql (Interactive SQL) is a versatile command-line utility used for connecting to and interacting with various database systems. It primarily functions as an ODBC (Open Database Connectivity) client, enabling users to execute SQL queries, DDL (Data Definition Language) statements, and DML (Data Manipulation Language) commands directly from the terminal.

This tool is particularly useful for database administrators and developers for testing database connectivity, running ad-hoc queries, scripting database operations, and debugging SQL statements without the need for a full-fledged graphical client. While its core functionality revolves around executing SQL, different isql implementations (e.g., from unixODBC or specific database vendors) might offer varying features such as command history, output formatting options, and batch mode execution. Its primary strength lies in providing a quick and efficient way to interact with ODBC-compliant databases.

The functionality and available options of isql can vary significantly depending on its specific implementation, as it's a generic name used by various database systems or ODBC driver providers (e.g., unixODBC, OpenLink Virtuoso). Users should consult the documentation for their particular isql version. It generally lacks advanced features found in graphical SQL clients.

isql is frequently used for:

• Testing Connectivity: Quickly verify if a database connection (via DSN or connection string) is working.
• Ad-hoc Queries: Execute one-off SQL queries for data retrieval or manipulation.
• Scripting: Run SQL scripts in batch mode for database initialization, data loading, or automated maintenance tasks.
• Debugging: Test specific SQL statements or stored procedures in a minimalist environment.

The concept of an 'isql' (Interactive SQL) client is fundamental to relational database management systems. While no single historical isql command exists across all Linux distributions or database vendors, the term generally refers to a command-line tool that allows users to type and execute SQL statements interactively. Implementations like the one provided by unixODBC emerged as part of efforts to standardize database connectivity (ODBC) across different platforms, offering a generic way to test and interact with various ODBC-compliant databases. Its usage reflects a long-standing need for simple, scriptable database interaction.

psql(1), mysql(1), sqlite3(1), odbcinst(1)