prepare-statement sql-exp &key database variable-types count flatp result-types => prepared-statement
A SQL expression.
A database.
A list.
A non-negative integer or
nil
.
A boolean.
A list of symbols.
The function
prepare-statement
returns a prepared-statement object for the SQL statement
sql-exp
in the database
database
.
sql-exp
can contain bind-variables in the form
:n
where
n
is a positive integer.
If database is supplied, then the prepared-statement is associated with the database. Otherwise set-prepared-statement-variables will do the association even if it is called without a database.
If variable-types is supplied, then it should be a list containing a keyword element for each bind-variable in sql-exp . It has an effect in two cases:
:string
forces the variable to be passed to the database as a string. That may be useful if you have numeric values in Lisp which are stored as strings in the database.
:date
cause an integer to be interpreted as a universal-time and be converted properly to an Oracle date.If variable-types is not supplied, then the types will be chosen dynamically from the values passed to set-prepared-statement-variables.
If count is supplied, then it should equal the maximum number of bind-variables in the sql-exp. If count is not supplied, then it is calculated from sql-exp .
flatp and result-types are interpreted the same as in select.
The result of
prepare-statement
is a prepared-statement. This can be used by calling set-prepared-statement-variables to actually bind the variable, and then use one of the querying or executing interfaces that take a SQL expression argument: execute-command, query, do-query, simple-do-query, map-query and the
loop for...being each record
construct.
A prepared-statement that is associated with a database should be destroyed (by destroy-prepared-statement) before the database is closed, otherwise it may leak memory.
Create a prepared-statement for a SQL expression:
(setq ps
(sql:prepare-statement
"insert into TABLETWO values(:1, :2)"))
Then insert records into TABLETWO (which has two columns) by repeatedly doing:
(sql:set-prepared-statement-variables
ps
(list value1 value2 ))
(sql:execute-command ps ))
query
do-query
simple-do-query
map-query
select
set-prepared-statement-variables
destroy-prepared-statement
LispWorks User Guide and Reference Manual - 21 Dec 2011