prepared-statement

问题 Using: MySQL 5.1 + PHP 5.3.5 MySQL: id in "table" is defined as: mediumint(6) zerofill not null I get the expected result when using: $mysqli->query("SELECT id FROM table WHERE id = 1"); while($row = $ret->fetch_array(MYSQLI_ASSOC)) $arr[] = $row; >>> $arr[0]["id"] = 000001 But not when I use prepared statement: $ret = $mysqli->prepare("SELECT id FROM table WHERE id = ?"); call_user_func_array(array($ret,"bind_param"),array("i",1)); $ret->execute(); $ret->store_result(); $meta = $ret->result

问题 I get the following error Fatal error: Call to a member function execute() on a non-object in /home/wt/public_html/view-reports.php on line 237 . I also see another problem. The variables generated doesn't echo the right corresponding data. For instance, $rep_type echo position. Could you please help me on this. Thank you! Test site url is here. ethioserver.com/~wt/view-reports.php?rep_id=144 The problem is not visible in wampserver. The php version in both servers is 5.4. The main code is

问题 In continuation to a previous case (a solution by @Erwin Brandstetter), in which a dynamic SELECT query that uses a 'prepare' statement was created and then was executed by calling it, as below: --the function for making the prepare statement: CREATE OR REPLACE FUNCTION f_prep_query (_tbl regclass, _prefix text) RETURNS void AS $func$ DECLARE _prep_qry text := ( SELECT 'PREPARE stmt_dyn AS SELECT ' || string_agg(quote_ident(attname), ',' ORDER BY attname) || ' FROM ' || _tbl FROM pg_attribute

问题 I have set a GiST pg_trgm index on the name column of the files table. The simplified query of the prepared statement looks like this: SELECT * FROM files WHERE name LIKE $1; The $1 param will be composed of % + user query + % . Since the input might also be an empty string this might result in %% . Does an "empty" LIKE ( %% ) result in performance degradation? Should I build a new query in that case, or does it not matter? 回答1: Postgres 9.2 or later is generally smart enough to realize that

问题 I'm new to mysql and php and wanted to clarify something on prepared-statements. All the examples I've seen only add params for the actual data in the table, is it bad practice to paramaterise all the fields so there are less statements? e.g. UPDATE ? SET ?=? WHERE ID=? Thank you 回答1: You cannot parameterize identifiers. You can only parameterize data . Otherwise the main point of parameterization, the separation between statement structure and data , is pretty moot. Understand that

问题 Ok, going to reword this question as i made it a bit too complicated before. i want to take this: con.setAutoCommit(false); String tempforbatch; Statement stmt = con.createStatement(); for (int i = 0; i < tables.length; i++) { tempforbatch = "INSERT INTO " + tables[i] + " VALUES ('" + values[i] + "')"; stmt.addBatch(tempforbatch); } stmt.executeBatch(); and turn it into something exactly the same, only using: PreparedStatement stmt = con.prepareStatement("INSERT INTO table_name VALUES (?, ?)"

问题 I'm using PostgreSQL's function query_to_xml function to generate XML of a query result. SELECT * FROM query_to_xml( 'SELECT * from some_table WHERE id = ?',true,false,'') Problem is, when I use it from JDBC, with prepared Statements the '?' is ignored, so Postgres says: "The column index is out of range..." Is there any possible solution to pass parameters to such a query ? 回答1: Try to move the ? outside the string literal: SELECT * FROM query_to_xml( 'SELECT * from some_table WHERE id = '||

问题 I am using REDSHIFT for the below question, Here is problem and I am looking for solution. I have 2 tables, one table contains the column combinations on which the second table should group the results by. Table 1 containing column combinations (This is output from a stored procedure): COMBINATIONS fruit_combinations banana,'ALL' banana, orange Table 2 containing fruit_baskets: FRUIT_BASKET BANANA ORANGE USER_COUNT b1 o1 5 b1 o2 10 Result set: FRUIT_BASKET_AGG BANANA ORANGE USER_COUNT b1 'ALL

问题 I have done this before but am quite new to mysqli and prepared statements (as I'm sure you can see from this issue). Where am I going wrong? here is my connection function (part of the 'Connect' class) public function site_db() { // Connect to MySQL $link = mysqli_connect(SITE_HOST, SITE_ID, SITE_PW, SITE_DB); // Check for Errors if(mysqli_connect_errno()) { //echo mysqli_connect_error(); //shouldnt show client specific error information. die('Error connecting to mysql database please report

问题 I have a doubt related to Prepared Statement in Java as I don't know much about it. I have a use case in which I have to use PreparedStatement. But I am just thinking before writing code that: while(...) { if(...) { preparedStatement.setString(1, fname); preparedStatement.setString(2, lname); ... preparedStatement.addBatch(); } } preparedStatement.executeBatch(); Lets Consider the above code. There is a while loop which will do some stuff and then check some condition and then add the batch