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Digg pg_prepare
Submits a request to create a prepared statement with the
given parameters, and waits for completion.
(PHP 5 >= 5.1.0)
pg_prepare() creates a prepared statement for later execution with pg_execute() or pg_send_execute(). This feature allows commands that will be used repeatedly to be parsed and planned just once, rather than each time they are executed. pg_prepare() is supported only against PostgreSQL 7.4 or higher connections; it will fail when using earlier versions. The function creates a prepared statement named stmtname from the query string, which must contain a single SQL command. stmtname may be "" to create an unnamed statement, in which case any pre-existing unnamed statement is automatically replaced; otherwise it is an error if the statement name is already defined in the current session. If any parameters are used, they are referred to in the query as $1, $2, etc.
Prepared statements for use with pg_prepare() can also be created by
executing SQL Parameters
ExamplesExample 1962. Using pg_prepare()<?php
See Also
Code Examples / Notes » pg_preparedavid
SQL is often a complicated piece of code by itself, so you may wish put it inside a "here doc." This will help you read it wherever it appears and test it by itself via a command-line or gui client. $sql = <<<SQL SELECT a.foo, b.bar, c.baz FROM table_a a LEFT JOIN table_b b ON ( a.a_id = b.a_id ) JOIN table_c c ON ( b.c_id = c.c_id ) WHERE c.name = $1 SQL; scott dot marlowe
Note that if you are preparing a query with an in clause with a list of items, you will need to prepare each item separately. $result = pg_prepare($dbconn, "my_query", 'SELECT * FROM shops WHERE name IN($1,$2,$3)'); $result = pg_execute($dbconn, "my_query", array("coffee", "beer", "hard")); This means that you can't just prepare a query with an arbitrary in() list. rodrigo
If you decide to deallocate (unprepare) a previously prepared sql command it might be better to quote the sql name as in DEALLOCATE "theNameOfMySQL" instead of (the more natural) DEALLOCATE theNameOfMySQL PostgerSQL preserves the case of your identifiers if, and only if, you quote them. The pg_prepare function preserves the case of the sql name you use. A complete example would be $sql = 'SELECT * FROM user WHERE cod_user = $1'; $sqlName = 'selectUserByCode'; if (!pg_prepare ($sqlName, $sql)) { die("Can't prepare '$sql': " . pg_last_error()); } $rs = pg_execute($sqlName, array(1)); do whatever you want with $rs and finally $sql = sprintf( 'DEALLOCATE "%s"', pg_escape_string($sqlName) ); if(!pg_query($sql)) { die("Can't query '$sql': " . pg_last_error()); } mike
I had some problems with this function. When you use pg_prepare() with a function like date_trunc('day', $1) you need to specify the data type. The solution was use the Pear MDB2 but with some changes in code. The original code try to use pg_prepare() too, with errors. |
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pg_affected_rows pg_cancel_query pg_client_encoding pg_close pg_connect pg_connection_busy pg_connection_reset pg_connection_status pg_convert pg_copy_from pg_copy_to pg_dbname pg_delete pg_end_copy pg_escape_bytea pg_escape_string pg_execute pg_fetch_all_columns pg_fetch_all pg_fetch_array pg_fetch_assoc pg_fetch_object pg_fetch_result pg_fetch_row pg_field_is_null pg_field_name pg_field_num pg_field_prtlen pg_field_size pg_field_table pg_field_type_oid pg_field_type pg_free_result pg_get_notify pg_get_pid pg_get_result pg_host pg_insert pg_last_error pg_last_notice pg_last_oid pg_lo_close pg_lo_create pg_lo_export pg_lo_import pg_lo_open pg_lo_read_all pg_lo_read pg_lo_seek pg_lo_tell pg_lo_unlink pg_lo_write pg_meta_data pg_num_fields pg_num_rows pg_options pg_parameter_status pg_pconnect pg_ping pg_port pg_prepare pg_put_line pg_query_params pg_query pg_result_error_field pg_result_error pg_result_seek pg_result_status pg_select pg_send_execute pg_send_prepare pg_send_query_params pg_send_query pg_set_client_encoding pg_set_error_verbosity pg_trace pg_transaction_status pg_tty pg_unescape_bytea pg_untrace pg_update pg_version |
