Common methods for using adodb

The above constants are in adodb. inc. the index in the record set returned by the value ADODB_FETCH_NUM defined in php, that is, the value of the variable $ ADODB_FETCH_MODE, is in the numerical form, that is, the record set format returned by the sort order value of the database field
Define ('adodb _ FETCH_DEFAULT ', 0 );
Define ('adodb _ FETCH_NUM ', 1 );
Define ('adodb _ FETCH_ASSOC ', 2 );
Define ('adodb _ FETCH_BOTH ', 3 );
The above constants are defined in adodb. inc. php, that is, the value that can be set by the variable $ ADODB_FETCH_MODE.
Commonly used: ADODB_FETCH_NUM or ADODB_FETCH_ASSOC
The index in the record set returned by ADODB_FETCH_NUM is in the numerical format, that is, the sort order value of the database fields.
The index in the record set returned by ADODB_FETCH_ASSOC is the field name of the original database.
Both ADODB_FETCH_BOTH and ADODB_FETCH_DEFAULT return the values of ADODB_FETCH_NUM and ADODB_FETCH_ASSOC at the same time, which are not supported by some databases.
An example:


$ ADODB_FETCH_MODE = ADODB_FETCH_NUM;
$ Rs1 = $ db-> Execute ('select * from table ');
$ ADODB_FETCH_MODE = ADODB_FETCH_ASSOC;
$ Rs2 = $ db-> Execute ('select * from table ');
Print_r ($ rs1-> fields); # The returned array is array ([0] => 'v0', [1] => 'v1 ')
Print_r ($ rs2-> fields); # The returned array is: array (['col1'] => 'v0', ['col2'] => 'v1 ')


<? Php
/*
Common methods for using ADODB
Collation: FEIBA Youxia QQ: 8527385 E-mail: liuchengcn # 163.com
If any error occurs, please forgive me and notify me via QQ or email. thank you.
*/
// Define database variables
$ DB_TYPE = "mysql ";
$ DB_HOST = "localhost ";
$ DB_USER = "root ";
$ DB_PASS = "";
$ DB_DATABASE = "ai-part ";
Require_once ("../adodb. inc. php ");
$ Db = NewADOConnection ("$ DB_TYPE"); // create a database object
$ Db-> debug = true; // DEBUG test of the database. this parameter can be set to true during program development. comment out this line in the official version (the default value is false)
$ ADODB_FETCH_MODE = ADODB_FETCH_ASSOC;
/*
Returned record set form
Define ('adodb _ FETCH_DEFAULT ', 0 );
Define ('adodb _ FETCH_NUM ', 1 );
Define ('adodb _ FETCH_ASSOC ', 2 );
Define ('adodb _ FETCH_BOTH ', 3 );
The above constants are defined in adodb. inc. php, that is, the value that can be set by the variable $ ADODB_FETCH_MODE.
Commonly used: ADODB_FETCH_NUM or ADODB_FETCH_ASSOC
The index in the record set returned by ADODB_FETCH_NUM is in the numerical format, that is, the sort order value of the database fields.
The index in the record set returned by ADODB_FETCH_ASSOC is the field name of the original database.
Both ADODB_FETCH_BOTH and ADODB_FETCH_DEFAULT return the values of ADODB_FETCH_NUM and ADODB_FETCH_ASSOC at the same time, which are not supported by some databases.
An example:
 
$ ADODB_FETCH_MODE = ADODB_FETCH_NUM;
$ Rs1 = $ db-> Execute ('select * from table ');
$ ADODB_FETCH_MODE = ADODB_FETCH_ASSOC;
$ Rs2 = $ db-> Execute ('select * from table ');
Print_r ($ rs1-> fields); # The returned array is array ([0] => 'v0', [1] => 'v1 ')
Print_r ($ rs2-> fields); # The returned array is: array (['col1'] => 'v0', ['col2'] => 'v1 ')
*/
 
// Connect to the database. The methods include Connect, PConnect, and NConnect. generally, Connect. NConnect is used to Connect to a special database.
If (! @ $ Db-> Connect ("$ DB_HOST", "$ DB_USER", "$ DB_PASS", "$ DB_DATABASE ")){
Exit ('server busy, please visit later ');
}
 
/*
$ Db-> $ rs-> usage of this class
Execute ($ SQL, $ inputarr = false), Execute the $ SQL statement in the parameter, followed by the $ inputarr parameter, which is generally not required
SelectLimit ($ SQL, $ numrows =-1, $ offset =-1, $ inputarr = false) $ numrows: get several records, $ offset, starting from the number of records, selectLimit, usually used for paging, or when only a few records are Retrieved
*/
// Example: retrieve multiple records
$ SQL = "SELECT * FROM table ORDER BY id DESC ";
If (! $ Rs = $ db-> Execute ($ SQL) {// Execute the SQL statement and return the result to the $ rs variable.
Echo $ db-> ErrorMsg (); // The error message is printed.
$ Db-> Close (); // Close the database
Exit ();
}
While (! $ Rs-> EOF) {// traverses the record set
Echo $ rs-> fields ['username'].'
'; // Print_r ($ rs-> fields). try $ rs-> fields ['Field name'] and return the value in this field.
$ Rs-> MoveNext (); // point the pointer to the next record. if you don't need it, an endless loop will occur!
}
$ Rs-> Close (); // Close it to release the memory. Close it once after each operation to develop a good habit of programming.
 
// Insert a new record
$ SQL = "INSERT table (user_type, username) VALUES (3, 'lieng eng ')";
$ Db-> Execute ($ SQL );
// Update records
$ SQL = "UPDATE table SET user_type = 3 WHERE id = 2 ";
$ Db-> Execute ($ SQL );
// Delete a record
$ SQL = "DELETE FROM table WHERE id = 2 ";
$ Db-> Execute ($ SQL );
 
// Retrieve a single record
// $ Db-> GetRow ($ SQL): retrieves the first record in SQL and returns an array. If an error occurs, false is returned.
$ SQL = "SELECT username, password, user_type FROM table WHERE id = 3 ";
$ Data_ary = $ db-> GetRow ($ SQL );
If ($ data_ary = false) {// if you use =, it may not be the result you want.
Echo 'This record is not found ';
Exit ();
} Else {
Echo $ data_ary ['username']. ''. $ data_ary ['password'].''. $ data_ary ['User _ type'].'
';
}
// $ Rs is not used here, and $ rs-> Close () is not required ();
// Another method (it is better and convenient to use the above method)
$ SQL = "SELECT username, password, user_type FROM table WHERE id = 3 ";
If (! $ Rs = $ db-> Execute ($ SQL )){
Echo $ db-> ErrorMsg ();
$ Db-> Close ();
Exit ();
}
If (! $ Result = $ rs-> FetchRow ()){
Echo 'This record is not found ';
Exit ();
} Else {
Echo $ result ['username']. ''. $ result ['password'].''. $ result ['User _ type'].'
';
}
 
// $ Db-> GetOne ($ SQL) retrieves the value of the first field of the first record in SQL. If an error occurs, false is returned.
$ SQL = "SELECT COUNT (id) FROM table ";
$ Record_nums = $ db-> GetOne ($ SQL );
Echo $ record_nums;
$ SQL = "SELECT username, password, user_type FROM table WHERE user_id = 1 ";
$ Result = $ db-> GetOne ($ SQL );
Echo $ result; // The value of username in the record.
/*
When adding, modifying, and deleting records, you must use $ db-> qstr () to process string-type fields and numeric fields, data judgment should be performed before
Update record. note: This is the case where magic_quotes is set to Off in php. ini. if you are not sure, you can use
$ Db-> qstr ($ content, get_magic_quotes_gpc ())
Note: content = the right side of the equal sign does not have single quotation marks
*/
$ SQL = "UPDATE table SET content =". $ db-> qstr ($ content). "WHERE id = 2 ";
$ Db-> Execute ($ SQL );
 
 
/* $ Db-> Insert_ID (), no parameter. the ID value of the record just inserted is returned. only some databases and databases with the auto-increment function are supported, such as PostgreSQL, mySQL and MS SQL
*/
// Example:
$ SQL = "INSERT table (user_type, username) VALUES (3, 'lieng eng ')";
$ Db-> Execute ($ SQL );
$ Data_id = $ db-> Insert_ID ();
Echo $ data_id;
 
/* $ Db-> GenID ($ seqName = 'adodbseq ', $ startID = 1) to generate an ID value. $ seqName: name of the database table used to generate this ID. $ startID: start value. Generally, you do not need to set it. it automatically adds the value in $ seqName to 1. some databases are supported. some databases are not supported.
 
Insert_ID, GenID. Generally, I use GenID, which is used only when the ID of a record is to be obtained immediately after it is inserted.
*/
/* Example:
Create a table named user_id_seq with only one field, id, int (10), not null, and insert a record with a value of 0.
*/
$ User_id = $ db-> GenID ('User _ id_seq ');
$ SQL = "INSERT table (id, user_type, username) VALUES (". $ user_id. ", 3, 'lieng eng ')";
$ Db-> Execute ($ SQL );
 
/*
$ Rs-> RecordCount (), retrieves the total number of record sets, no parameter
It seems that the number of retrieved records is obtained using the count () array method.
If a large amount of data is retrieved, the efficiency is slow. we recommend that you use the COUNT (*) method in SQL.
$ SQL = "select count (*) FROM table". when using this method, do not add order by to SQL, which will reduce the execution speed.
 
Example:
*/
$ SQL = "SELECT * FROM table ORDER BY id DESC ";
If (! $ Rs = $ db-> Execute ($ SQL )){
Echo $ db-> ErrorMsg ();
$ Db-> Close ();
Exit ();
}
$ Record_nums = $ rs-> RecordCount ();
 
/*
If you want to perform the same loop processing for a result set twice, you can use the following method:
The following is an example. it only describes how to use $ rs-> MoveFirst ().
*/
$ SQL = "SELECT * FROM table ORDER BY id DESC ";
If (! $ Rs = $ db-> Execute ($ SQL )){
Echo $ db-> ErrorMsg ();
$ Db-> Close ();
Exit ();
}
$ Username_ary = array ();
While (! $ Rs-> EOF ){
$ Username_ary [] = $ rs-> fields ['username']
Echo $ rs-> fields ['username'].'
'; // Print_r ($ rs-> fields). try $ rs-> fields ['Field name'] and return the value in this field.
$ Rs-> MoveNext (); // point the pointer to the next record. if you don't need it, an endless loop will occur!
}
$ Username_ary = array_unique ($ username_ary );
 
$ Rs-> MoveFirst (); // returns the pointer to the first record, with no parameter
While (! $ Rs-> EOF ){
Echo $ rs-> fields ['password'].'
'; // Print_r ($ rs-> fields). try $ rs-> fields ['Field name'] and return the value in this field.
$ Rs-> MoveNext (); // point the pointer to the next record. if you don't need it, an endless loop will occur!
}
$ Rs-> Close ();
 
 
/*
When the program on this page and the operations on the database are completed, $ db-> Close ();
 
*/
 
$ Db-> Close ();
 
/* A good method */
If (isset ($ db )){
$ Db-> Close ();
}
?>