DbiXX is not a mandatory part of the CppCMS framework; it is just a general purpose library to execute SQL queries in a safe way. |
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Let's see a simple example: |
Let's see a simple example. You can find the code of this example within the cppcms source code, at `cppcms/examples/dbixx/dbi.cpp`. |
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#include <dbixx/dbixx.h> |
#include <iostream> |
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using namespace dbixx; |
using namespace std; |
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int main() |
{ |
try { |
session sql("sqlite3"); |
sql.param("dbname","test.db"); |
sql.param("sqlite3_dbdir","./"); |
sql.connect(); |
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sql<<"DROP TABLE IF EXISTS users"; |
sql.exec(); |
sql<<"CREATE TABLE users ( " |
" id integer primary key not null, " |
" name varchar(128) not null " |
");"; |
sql.exec(); |
sql<<"INSERT INTO users(id,name) VALUES(?,?)", |
1,"Moshe",exec(); |
sql<<"INSERT INTO users(id,name) VALUES(?,?)", |
2,"Yossi",exec(); |
sql<<"SELECT name FROM users WHERE id=?",1; |
row r; |
if(sql.single(r)) { |
string name; |
r>>name; |
cout<<name<<endl; |
} |
else { |
cout<<"No user with id="<<1<<endl; |
} |
result res; |
sql<<"SELECT id,name FROM users"; |
sql.fetch(res); |
cout<<"There are "<<res.rows()<<" users\n"; |
while(res.next(r)) { |
int id; |
string name; |
r>>id>>name; |
cout<<id<<"\t"<<name<<endl; |
} |
} |
catch(std::exception const &e) { |
cerr<<e.what()<<endl; |
return 1; |
} |
return 0; |
} |
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First we create a sql session object and load the driver "sqlite3". Then we setup all the mandatory parameters needed by the driver and create a connection. |
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session sql("sqlite3"); |
sql.param("dbname","test.db"); |
sql.param("sqlite3_dbdir","./"); |
sql.connect(); |
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Then we perform queries. First we prepare them using |
"iostreams like" style: |
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sql<<"DROP TABLE IF EXISTS users"; |
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and then execute the operation: |
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sql.exec(); |
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There is a syntactic sugar for this operation: |
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sql<<"DROP TABLE IF EXISTS users",exec(); |
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Then we want to execute some commands using parameters |
binding: |
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sql<<"INSERT INTO users(id,name) VALUES(?,?)", |
1,"Moshe",exec(); |
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First we load our query. Each "?" represents a bound parameter. Then, using overloaded comma operator, we bind actual values: the integer "1" and the string "Moshe". Note: every bound string is automatically escaped. |
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Now we want to fetch a single row of data. First, we bind the query and its parameters as before. |
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sql<<"SELECT name FROM users WHERE id=?",1; |
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But now, we store the output data in a single row class. |
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row r; |
if(sql.single(r)) { |
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If the result wasn't an empty set, the condition is true and we can readout the data from the row, using the "iostreams" like interface. |
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r>>name; |
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Now, we want to fetch some bigger data set. In this case we |
use the class result that stores the output data. We use: |
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result res; |
sql.fetch(res); |
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Now we can find out the number of rows calling `res.rows()` and iterate over each row calling `res.next(r)`. |
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Now, you can read the full [DbiXX Library API](http://art-blog.no-ip.info/wikipp/en/page/ref_dbixx) |
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