prepared-statement

问题 If I remember correctly, I think Jeff has mentioned in the Stack Overflow podcast a possible weakness in SQL prepared statements. I'm wondering what kind(s) of weakness(es) did he refer to? Was it possibly just about inappropriate usage thereof, or something more sinister? The podcast, to my remembering, didn't go deeper into the subject, it was just a pass-by-remark. 回答1: I think what he said was that, when you use Prepared Statements, SQL server could cache your query execution plan, so,

问题 What are the advantages of using prepared statements with MySQLi? If the only purpose is to secure the query, isn't it better to clean the query using something like mysqli_real_escape_string instead of writing so many lines of code for each query (like prepare, bind_param, execute, close etc.)? 回答1: Preparing statements is not just for code security. It helps the SQL server parse your statement and generate an execution plan for your query. If you run a SELECT 1000 times then the SQL server

问题 I have a typical crosstab query with static parameters. It works fine with createStatement. I want to use preparestatement to query instead. String query = "SELECT * FROM crosstab( 'SELECT rowid, a_name, value FROM test WHERE a_name = ''att2'' OR a_name = ''att3'' ORDER BY 1,2' ) AS ct(row_name text, category_1 text, category_2 text, category_3 text);"; PreparedStatement stat = conn.prepareStatement(query); ResultSet rs = stat.getResultSet(); stat.executeQuery(query); rs = stat.getResultSet()

问题 Quoting MySQL INSERT manual - same goes for UPDATE: Use the keyword DEFAULT to set a column explicitly to its default value. This makes it easier to write INSERT statements that assign values to all but a few columns, because it enables you to avoid writing an incomplete VALUES list that does not include a value for each column in the table. Otherwise, you would have to write out the list of column names corresponding to each value in the VALUES list. So in short if I write INSERT INTO table1

问题 This question already has answers here : Does Python support MySQL prepared statements? (7 answers) Closed 3 years ago . Does MySQLdb support server-side prepared statements? I can't figure this out from its manual. 回答1: Check the MySQLdb Package Comments: "Parameterization" is done in MySQLdb by escaping strings and then blindly interpolating them into the query, instead of using the MYSQL_STMT API. As a result unicode strings have to go through two intermediate representations (encoded

问题 I just switched to PDO from mySQLi (from mySQL) and it's so far good and easy, especially regarding prepared statements This is what I have for a select with prepared statement Main DB file (included in all pages): class DBi { public static $conn; // this I need to make the connection "global" } try { DBi::$conn = new PDO("mysql:host=$dbhost;dbname=$dbname;charset=utf8", $dbuname, $dbpass); DBi::$conn->setAttribute(PDO::ATTR_DEFAULT_FETCH_MODE, PDO::FETCH_ASSOC); DBi::$conn->setAttribute(PDO:

问题 I just switched to PDO from mySQLi (from mySQL) and it's so far good and easy, especially regarding prepared statements This is what I have for a select with prepared statement Main DB file (included in all pages): class DBi { public static $conn; // this I need to make the connection "global" } try { DBi::$conn = new PDO("mysql:host=$dbhost;dbname=$dbname;charset=utf8", $dbuname, $dbpass); DBi::$conn->setAttribute(PDO::ATTR_DEFAULT_FETCH_MODE, PDO::FETCH_ASSOC); DBi::$conn->setAttribute(PDO:

问题 Does php 5.6 support prepared statement ? As I'm getting this error : "PHP Fatal error: Call to a member function prepare() on resource " Here Is the code : $testSql = $ce_conn -> prepare('select transaction_id from tbl_sales_revenue limit 1'); $testSql -> execute(); $testSql -> bind_result($transaction_id); $testSql -> fetch(); $testSql -> close(); function connectCE() { global $config; $ce_conn = mysql_connect($config['Datasources']['CE']['host'], $config['Datasources']['CE']['username'],

问题 I have this database table: create table users( id int not null auto_increment, fn varchar(30), ln varchar(30), sex char, email varchar(60), country varchar(40), username varchar(30), password varchar(100), primary key(id) ); When I run this code, I am getting an error: Parameter index out of range (8 > number of parameters, which is 7). I also tried changing setString(1,fn) but it's not working. try{ String INSERT="INSERT INTO users (fn,ln,,sex,email,country,username,password) VALUES (?,?,?,

问题 1) Can I use one prepared statement to pass data to multiple tables from java? where I am using JDBC driver. try { conn = ac.getConnection(); String insert = "INSERT INTO PPN_WORKFLOW(C2_F_Date,C2_Completed) VALUES(?,?)"; stmt = conn.prepareStatement(insert); stmt.setDate(1, date);//question 2 stmt.setInt(2, 1); stmt.executeUpdate(); stmt.close(); String insert2 = "INSERT INTO CREATE_ERF(Purc_Part_New_F_Date,Purc_Part_New_Completed) " + "VALUES(?,?)"; stmt = conn.prepareStatement(insert2);