Es sql queryvalue

Overview

Syntax: es_sql queryvalue <db-name> <variable> "<SQL-string>"

Variation of this command that doesn't expand variables: es_xsql queryvalue

Description

Same as es_sql query, but stores only the first row/column value into variable. Useful for COUNT()/SUM() queries.

Parameters

• db-name - The name of the database to query. The database must have been opened first by a call to es_sql open
• variable - A variable to store the value into.
• "SQL-string - A SQL statement that conforms to the Structured Query Language (SQL) syntax supported by SQLite3. Must be in quotation marks, with strings in single quotes.

Examples

See the ServerMail example in ES v1.5 for a detailed example.

// open a SQLite database file, creates/opens es_mydb.sqldb
es_sql open mydb |myscript
es_xset myvar 0
es_sql queryvalue mydb myvar "SELECT * FROM mytable WHERE myname='Mattie';"
if (server_var(myvar) != 0) then es_xmsg Found a result!

Notes

• Must call es_sql open on the database before trying queries.
• This is a synchronous call.
• SQLite has very good performance, but it will be dependent on just how large the table is.
• For complicated queries or large tables, it's recommended that you wait to perform the query until a more acceptable time.
• Requires EventScripts v1.5.

See also

• es_sql open
• es_sql query
• es_sql close
• es_formatqv -- should always be used to format query statements with user-provided data. Protects your database.
• SQLite syntax
• SQLite
• Cool SQLite admin tool for creating and modifying database files outside of ES.

• Forum search for Es_sql_queryvalue