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DatabaseError

Script function

world.DatabaseError

Read about scripting

Type

Method

Summary

Returns an English string describing the most recent SQL error

Prototype

BSTR DatabaseError(BSTR DbName);

View list of data type meanings

Description

Call this after one of the other Database routines returns an error code (generally, a code other than 0, 100 or 101).

This will return an explanatory string.

To help with debugging however, codes 100 and 101 also return:

100: "row ready"
101: "finished"

Warning: Since you do not pass the error code into this function, it will not correctly handle the "internal" MUSHclient errors (such as database not open). To handle them correctly you need to test for negative error numbers, as shown in the Lua example below.


Available in MUSHclient version 4.40 onwards.



Lua example

print (DatabaseError ("db"))

--

---
--- Example of handling internal errors, and SQLite3 errors
---

local MUSHclient_Database_Errors = {
  [-1] = "Database id not found",
  [-2] = "Database not open",
  [-3] = "Already have prepared statement",
  [-4] = "Do not have prepared statement",
  [-5] = "Do not have a valid row",
  [-6] = "Database already exists under a different disk name",
  [-7] = "Column number out of range",
  } -- end of MUSHclient_Database_Errors

-- check for errors on a DatabaseXXXXX call
function dbcheck (code)

 if code == sqlite3.OK or       -- no error
    code == sqlite3.ROW or      -- completed OK with another row of data
    code == sqlite3.DONE then   -- completed OK, no more rows
    return code
  end -- if code OK

  -- DatabaseError won't return the negative errors  
  local err = MUSHclient_Database_Errors [code] or DatabaseError(db)
  DatabaseExec (db, "ROLLBACK")  -- rollback any transaction to unlock the database
  error (err, 2)                 -- show error in caller's context

end -- dbcheck


Return value

The error message.


See Also ...

Topics

Database (SQLite)
Lua SQLite (database) interface
Scripting

Functions

(DatabaseChanges) Returns a count of the changes to the database by the most recent SQL statement
(DatabaseClose) Closes an SQLite database
(DatabaseColumnName) Find the name of a specified column returned by an SQL statement
(DatabaseColumnNames) Return a table of all the columns returned by an SQL statement
(DatabaseColumns) Find how many columns will be returned by an SQL statement
(DatabaseColumnText) Returns the contents of an SQL column, as text
(DatabaseColumnType) Returns the type of data in an SQL column
(DatabaseColumnValue) Returns the contents of an SQL column, as text, float, integer, or null
(DatabaseColumnValues) Returns the contents of all the SQL columns after a step
(DatabaseExec) Executes SQL code against an SQLite database
(DatabaseFinalize) Finalizes (wraps up) a previously-prepared SQL statement
(DatabaseGetField) Returns a single field from an SQL database
(DatabaseInfo) Returns information about a database
(DatabaseLastInsertRowid) Returns the most recently automatically allocated database key
(DatabaseList) Lists all databases
(DatabaseOpen) Opens an SQLite database
(DatabasePrepare) Prepares an SQL statement for execution
(DatabaseReset) Resets a previously-prepared SQL statement to the start
(DatabaseStep) Executes a previously-prepared SQL statement
(DatabaseTotalChanges) Returns a count of the total changes to the database

(Help topic: function=DatabaseError)

Documentation contents page


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