A PHP Error was encountered

Severity: Warning

Message: date() [function.date]: It is not safe to rely on the system's timezone settings. You are *required* to use the date.timezone setting or the date_default_timezone_set() function. In case you used any of those methods and you are still getting this warning, you most likely misspelled the timezone identifier. We selected 'Asia/Krasnoyarsk' for '+07/7.0/no DST' instead

Filename: libraries/Log.php

Line Number: 86

A PHP Error was encountered

Severity: Warning

Message: date() [function.date]: It is not safe to rely on the system's timezone settings. You are *required* to use the date.timezone setting or the date_default_timezone_set() function. In case you used any of those methods and you are still getting this warning, you most likely misspelled the timezone identifier. We selected 'Asia/Krasnoyarsk' for '+07/7.0/no DST' instead

Filename: libraries/Log.php

Line Number: 86

A PHP Error was encountered

Severity: Warning

Message: date() [function.date]: It is not safe to rely on the system's timezone settings. You are *required* to use the date.timezone setting or the date_default_timezone_set() function. In case you used any of those methods and you are still getting this warning, you most likely misspelled the timezone identifier. We selected 'Asia/Krasnoyarsk' for '+07/7.0/no DST' instead

Filename: libraries/Log.php

Line Number: 86

A PHP Error was encountered

Severity: Warning

Message: date() [function.date]: It is not safe to rely on the system's timezone settings. You are *required* to use the date.timezone setting or the date_default_timezone_set() function. In case you used any of those methods and you are still getting this warning, you most likely misspelled the timezone identifier. We selected 'Asia/Krasnoyarsk' for '+07/7.0/no DST' instead

Filename: libraries/Log.php

Line Number: 86

A PHP Error was encountered

Severity: Warning

Message: date() [function.date]: It is not safe to rely on the system's timezone settings. You are *required* to use the date.timezone setting or the date_default_timezone_set() function. In case you used any of those methods and you are still getting this warning, you most likely misspelled the timezone identifier. We selected 'Asia/Krasnoyarsk' for '+07/7.0/no DST' instead

Filename: libraries/Log.php

Line Number: 86

A PHP Error was encountered

Severity: Warning

Message: date() [function.date]: It is not safe to rely on the system's timezone settings. You are *required* to use the date.timezone setting or the date_default_timezone_set() function. In case you used any of those methods and you are still getting this warning, you most likely misspelled the timezone identifier. We selected 'Asia/Krasnoyarsk' for '+07/7.0/no DST' instead

Filename: libraries/Log.php

Line Number: 86

A PHP Error was encountered

Severity: Warning

Message: date() [function.date]: It is not safe to rely on the system's timezone settings. You are *required* to use the date.timezone setting or the date_default_timezone_set() function. In case you used any of those methods and you are still getting this warning, you most likely misspelled the timezone identifier. We selected 'Asia/Krasnoyarsk' for '+07/7.0/no DST' instead

Filename: libraries/Log.php

Line Number: 86

A PHP Error was encountered

Severity: Warning

Message: date() [function.date]: It is not safe to rely on the system's timezone settings. You are *required* to use the date.timezone setting or the date_default_timezone_set() function. In case you used any of those methods and you are still getting this warning, you most likely misspelled the timezone identifier. We selected 'Asia/Krasnoyarsk' for '+07/7.0/no DST' instead

Filename: libraries/Log.php

Line Number: 86

A PHP Error was encountered

Severity: Warning

Message: date() [function.date]: It is not safe to rely on the system's timezone settings. You are *required* to use the date.timezone setting or the date_default_timezone_set() function. In case you used any of those methods and you are still getting this warning, you most likely misspelled the timezone identifier. We selected 'Asia/Krasnoyarsk' for '+07/7.0/no DST' instead

Filename: libraries/Log.php

Line Number: 86

A PHP Error was encountered

Severity: Warning

Message: date() [function.date]: It is not safe to rely on the system's timezone settings. You are *required* to use the date.timezone setting or the date_default_timezone_set() function. In case you used any of those methods and you are still getting this warning, you most likely misspelled the timezone identifier. We selected 'Asia/Krasnoyarsk' for '+07/7.0/no DST' instead

Filename: libraries/Log.php

Line Number: 86

A PHP Error was encountered

Severity: Warning

Message: date() [function.date]: It is not safe to rely on the system's timezone settings. You are *required* to use the date.timezone setting or the date_default_timezone_set() function. In case you used any of those methods and you are still getting this warning, you most likely misspelled the timezone identifier. We selected 'Asia/Krasnoyarsk' for '+07/7.0/no DST' instead

Filename: libraries/Log.php

Line Number: 86

A PHP Error was encountered

Severity: Warning

Message: date() [function.date]: It is not safe to rely on the system's timezone settings. You are *required* to use the date.timezone setting or the date_default_timezone_set() function. In case you used any of those methods and you are still getting this warning, you most likely misspelled the timezone identifier. We selected 'Asia/Krasnoyarsk' for '+07/7.0/no DST' instead

Filename: libraries/Log.php

Line Number: 86

A PHP Error was encountered

Severity: Warning

Message: date() [function.date]: It is not safe to rely on the system's timezone settings. You are *required* to use the date.timezone setting or the date_default_timezone_set() function. In case you used any of those methods and you are still getting this warning, you most likely misspelled the timezone identifier. We selected 'Asia/Krasnoyarsk' for '+07/7.0/no DST' instead

Filename: libraries/Log.php

Line Number: 86

A PHP Error was encountered

Severity: Warning

Message: date() [function.date]: It is not safe to rely on the system's timezone settings. You are *required* to use the date.timezone setting or the date_default_timezone_set() function. In case you used any of those methods and you are still getting this warning, you most likely misspelled the timezone identifier. We selected 'Asia/Krasnoyarsk' for '+07/7.0/no DST' instead

Filename: libraries/Log.php

Line Number: 86

A PHP Error was encountered

Severity: Warning

Message: date() [function.date]: It is not safe to rely on the system's timezone settings. You are *required* to use the date.timezone setting or the date_default_timezone_set() function. In case you used any of those methods and you are still getting this warning, you most likely misspelled the timezone identifier. We selected 'Asia/Krasnoyarsk' for '+07/7.0/no DST' instead

Filename: libraries/Log.php

Line Number: 86

A PHP Error was encountered

Severity: Warning

Message: date() [function.date]: It is not safe to rely on the system's timezone settings. You are *required* to use the date.timezone setting or the date_default_timezone_set() function. In case you used any of those methods and you are still getting this warning, you most likely misspelled the timezone identifier. We selected 'Asia/Krasnoyarsk' for '+07/7.0/no DST' instead

Filename: libraries/Log.php

Line Number: 86

A PHP Error was encountered

Severity: Warning

Message: date() [function.date]: It is not safe to rely on the system's timezone settings. You are *required* to use the date.timezone setting or the date_default_timezone_set() function. In case you used any of those methods and you are still getting this warning, you most likely misspelled the timezone identifier. We selected 'Asia/Krasnoyarsk' for '+07/7.0/no DST' instead

Filename: libraries/Log.php

Line Number: 86

A PHP Error was encountered

Severity: Warning

Message: date() [function.date]: It is not safe to rely on the system's timezone settings. You are *required* to use the date.timezone setting or the date_default_timezone_set() function. In case you used any of those methods and you are still getting this warning, you most likely misspelled the timezone identifier. We selected 'Asia/Krasnoyarsk' for '+07/7.0/no DST' instead

Filename: libraries/Log.php

Line Number: 86

A PHP Error was encountered

Severity: Warning

Message: date() [function.date]: It is not safe to rely on the system's timezone settings. You are *required* to use the date.timezone setting or the date_default_timezone_set() function. In case you used any of those methods and you are still getting this warning, you most likely misspelled the timezone identifier. We selected 'Asia/Krasnoyarsk' for '+07/7.0/no DST' instead

Filename: libraries/Log.php

Line Number: 86

A PHP Error was encountered

Severity: Warning

Message: date() [function.date]: It is not safe to rely on the system's timezone settings. You are *required* to use the date.timezone setting or the date_default_timezone_set() function. In case you used any of those methods and you are still getting this warning, you most likely misspelled the timezone identifier. We selected 'Asia/Krasnoyarsk' for '+07/7.0/no DST' instead

Filename: libraries/Log.php

Line Number: 86

A PHP Error was encountered

Severity: Warning

Message: date() [function.date]: It is not safe to rely on the system's timezone settings. You are *required* to use the date.timezone setting or the date_default_timezone_set() function. In case you used any of those methods and you are still getting this warning, you most likely misspelled the timezone identifier. We selected 'Asia/Krasnoyarsk' for '+07/7.0/no DST' instead

Filename: libraries/Log.php

Line Number: 86

A PHP Error was encountered

Severity: Warning

Message: date() [function.date]: It is not safe to rely on the system's timezone settings. You are *required* to use the date.timezone setting or the date_default_timezone_set() function. In case you used any of those methods and you are still getting this warning, you most likely misspelled the timezone identifier. We selected 'Asia/Krasnoyarsk' for '+07/7.0/no DST' instead

Filename: libraries/Log.php

Line Number: 86

A PHP Error was encountered

Severity: Warning

Message: date() [function.date]: It is not safe to rely on the system's timezone settings. You are *required* to use the date.timezone setting or the date_default_timezone_set() function. In case you used any of those methods and you are still getting this warning, you most likely misspelled the timezone identifier. We selected 'Asia/Krasnoyarsk' for '+07/7.0/no DST' instead

Filename: libraries/Email.php

Line Number: 691

A PHP Error was encountered

Severity: Warning

Message: date() [function.date]: It is not safe to rely on the system's timezone settings. You are *required* to use the date.timezone setting or the date_default_timezone_set() function. In case you used any of those methods and you are still getting this warning, you most likely misspelled the timezone identifier. We selected 'Asia/Krasnoyarsk' for '+07/7.0/no DST' instead

Filename: libraries/Email.php

Line Number: 696

A PHP Error was encountered

Severity: Warning

Message: date() [function.date]: It is not safe to rely on the system's timezone settings. You are *required* to use the date.timezone setting or the date_default_timezone_set() function. In case you used any of those methods and you are still getting this warning, you most likely misspelled the timezone identifier. We selected 'Asia/Krasnoyarsk' for '+07/7.0/no DST' instead

Filename: libraries/Log.php

Line Number: 86

A PHP Error was encountered

Severity: Warning

Message: date() [function.date]: It is not safe to rely on the system's timezone settings. You are *required* to use the date.timezone setting or the date_default_timezone_set() function. In case you used any of those methods and you are still getting this warning, you most likely misspelled the timezone identifier. We selected 'Asia/Krasnoyarsk' for '+07/7.0/no DST' instead

Filename: libraries/Log.php

Line Number: 86

A PHP Error was encountered

Severity: Warning

Message: date() [function.date]: It is not safe to rely on the system's timezone settings. You are *required* to use the date.timezone setting or the date_default_timezone_set() function. In case you used any of those methods and you are still getting this warning, you most likely misspelled the timezone identifier. We selected 'Asia/Krasnoyarsk' for '+07/7.0/no DST' instead

Filename: libraries/Log.php

Line Number: 86

A PHP Error was encountered

Severity: Warning

Message: date() [function.date]: It is not safe to rely on the system's timezone settings. You are *required* to use the date.timezone setting or the date_default_timezone_set() function. In case you used any of those methods and you are still getting this warning, you most likely misspelled the timezone identifier. We selected 'Asia/Krasnoyarsk' for '+07/7.0/no DST' instead

Filename: libraries/Log.php

Line Number: 86

A PHP Error was encountered

Severity: Warning

Message: date() [function.date]: It is not safe to rely on the system's timezone settings. You are *required* to use the date.timezone setting or the date_default_timezone_set() function. In case you used any of those methods and you are still getting this warning, you most likely misspelled the timezone identifier. We selected 'Asia/Krasnoyarsk' for '+07/7.0/no DST' instead

Filename: libraries/Log.php

Line Number: 86

A PHP Error was encountered

Severity: Warning

Message: Cannot modify header information - headers already sent by (output started at /home/samdictc/public_html/system/core/Exceptions.php:170)

Filename: libraries/Session.php

Line Number: 671

A PHP Error was encountered

Severity: Warning

Message: date() [function.date]: It is not safe to rely on the system's timezone settings. You are *required* to use the date.timezone setting or the date_default_timezone_set() function. In case you used any of those methods and you are still getting this warning, you most likely misspelled the timezone identifier. We selected 'Asia/Krasnoyarsk' for '+07/7.0/no DST' instead

Filename: libraries/Log.php

Line Number: 86

A PHP Error was encountered

Severity: Warning

Message: date() [function.date]: It is not safe to rely on the system's timezone settings. You are *required* to use the date.timezone setting or the date_default_timezone_set() function. In case you used any of those methods and you are still getting this warning, you most likely misspelled the timezone identifier. We selected 'Asia/Krasnoyarsk' for '+07/7.0/no DST' instead

Filename: libraries/Log.php

Line Number: 86

A PHP Error was encountered

Severity: Warning

Message: date() [function.date]: It is not safe to rely on the system's timezone settings. You are *required* to use the date.timezone setting or the date_default_timezone_set() function. In case you used any of those methods and you are still getting this warning, you most likely misspelled the timezone identifier. We selected 'Asia/Krasnoyarsk' for '+07/7.0/no DST' instead

Filename: libraries/Log.php

Line Number: 86

A PHP Error was encountered

Severity: Warning

Message: session_start() [function.session-start]: Cannot send session cookie - headers already sent by (output started at /home/samdictc/public_html/system/core/Exceptions.php:170)

Filename: libraries/facebook.php

Line Number: 37

A PHP Error was encountered

Severity: Warning

Message: session_start() [function.session-start]: Cannot send session cache limiter - headers already sent (output started at /home/samdictc/public_html/system/core/Exceptions.php:170)

Filename: libraries/facebook.php

Line Number: 37

A PHP Error was encountered

Severity: Warning

Message: date() [function.date]: It is not safe to rely on the system's timezone settings. You are *required* to use the date.timezone setting or the date_default_timezone_set() function. In case you used any of those methods and you are still getting this warning, you most likely misspelled the timezone identifier. We selected 'Asia/Krasnoyarsk' for '+07/7.0/no DST' instead

Filename: libraries/Log.php

Line Number: 86

A PHP Error was encountered

Severity: Warning

Message: date() [function.date]: It is not safe to rely on the system's timezone settings. You are *required* to use the date.timezone setting or the date_default_timezone_set() function. In case you used any of those methods and you are still getting this warning, you most likely misspelled the timezone identifier. We selected 'Asia/Krasnoyarsk' for '+07/7.0/no DST' instead

Filename: libraries/Log.php

Line Number: 86

A PHP Error was encountered

Severity: Warning

Message: Cannot modify header information - headers already sent by (output started at /home/samdictc/public_html/system/core/Exceptions.php:170)

Filename: core/Input.php

Line Number: 250

A PHP Error was encountered

Severity: Warning

Message: date() [function.date]: It is not safe to rely on the system's timezone settings. You are *required* to use the date.timezone setting or the date_default_timezone_set() function. In case you used any of those methods and you are still getting this warning, you most likely misspelled the timezone identifier. We selected 'Asia/Krasnoyarsk' for '+07/7.0/no DST' instead

Filename: libraries/Log.php

Line Number: 86

A PHP Error was encountered

Severity: Warning

Message: date() [function.date]: It is not safe to rely on the system's timezone settings. You are *required* to use the date.timezone setting or the date_default_timezone_set() function. In case you used any of those methods and you are still getting this warning, you most likely misspelled the timezone identifier. We selected 'Asia/Krasnoyarsk' for '+07/7.0/no DST' instead

Filename: libraries/Log.php

Line Number: 86

A PHP Error was encountered

Severity: Warning

Message: date() [function.date]: It is not safe to rely on the system's timezone settings. You are *required* to use the date.timezone setting or the date_default_timezone_set() function. In case you used any of those methods and you are still getting this warning, you most likely misspelled the timezone identifier. We selected 'Asia/Krasnoyarsk' for '+07/7.0/no DST' instead

Filename: libraries/Log.php

Line Number: 86

A PHP Error was encountered

Severity: Warning

Message: date() [function.date]: It is not safe to rely on the system's timezone settings. You are *required* to use the date.timezone setting or the date_default_timezone_set() function. In case you used any of those methods and you are still getting this warning, you most likely misspelled the timezone identifier. We selected 'Asia/Krasnoyarsk' for '+07/7.0/no DST' instead

Filename: libraries/Log.php

Line Number: 86

A PHP Error was encountered

Severity: Warning

Message: date() [function.date]: It is not safe to rely on the system's timezone settings. You are *required* to use the date.timezone setting or the date_default_timezone_set() function. In case you used any of those methods and you are still getting this warning, you most likely misspelled the timezone identifier. We selected 'Asia/Krasnoyarsk' for '+07/7.0/no DST' instead

Filename: libraries/Log.php

Line Number: 86

A PHP Error was encountered

Severity: Warning

Message: date() [function.date]: It is not safe to rely on the system's timezone settings. You are *required* to use the date.timezone setting or the date_default_timezone_set() function. In case you used any of those methods and you are still getting this warning, you most likely misspelled the timezone identifier. We selected 'Asia/Krasnoyarsk' for '+07/7.0/no DST' instead

Filename: libraries/Log.php

Line Number: 86

A PHP Error was encountered

Severity: Warning

Message: date() [function.date]: It is not safe to rely on the system's timezone settings. You are *required* to use the date.timezone setting or the date_default_timezone_set() function. In case you used any of those methods and you are still getting this warning, you most likely misspelled the timezone identifier. We selected 'Asia/Krasnoyarsk' for '+07/7.0/no DST' instead

Filename: libraries/Log.php

Line Number: 86

A PHP Error was encountered

Severity: Warning

Message: date() [function.date]: It is not safe to rely on the system's timezone settings. You are *required* to use the date.timezone setting or the date_default_timezone_set() function. In case you used any of those methods and you are still getting this warning, you most likely misspelled the timezone identifier. We selected 'Asia/Krasnoyarsk' for '+07/7.0/no DST' instead

Filename: libraries/Log.php

Line Number: 86

A PHP Error was encountered

Severity: Warning

Message: date() [function.date]: It is not safe to rely on the system's timezone settings. You are *required* to use the date.timezone setting or the date_default_timezone_set() function. In case you used any of those methods and you are still getting this warning, you most likely misspelled the timezone identifier. We selected 'Asia/Krasnoyarsk' for '+07/7.0/no DST' instead

Filename: libraries/Log.php

Line Number: 86

A PHP Error was encountered

Severity: Warning

Message: date() [function.date]: It is not safe to rely on the system's timezone settings. You are *required* to use the date.timezone setting or the date_default_timezone_set() function. In case you used any of those methods and you are still getting this warning, you most likely misspelled the timezone identifier. We selected 'Asia/Krasnoyarsk' for '+07/7.0/no DST' instead

Filename: libraries/Log.php

Line Number: 86

A PHP Error was encountered

Severity: Warning

Message: date() [function.date]: It is not safe to rely on the system's timezone settings. You are *required* to use the date.timezone setting or the date_default_timezone_set() function. In case you used any of those methods and you are still getting this warning, you most likely misspelled the timezone identifier. We selected 'Asia/Krasnoyarsk' for '+07/7.0/no DST' instead

Filename: libraries/Log.php

Line Number: 86

A PHP Error was encountered

Severity: Warning

Message: date() [function.date]: It is not safe to rely on the system's timezone settings. You are *required* to use the date.timezone setting or the date_default_timezone_set() function. In case you used any of those methods and you are still getting this warning, you most likely misspelled the timezone identifier. We selected 'Asia/Krasnoyarsk' for '+07/7.0/no DST' instead

Filename: libraries/Log.php

Line Number: 86

A PHP Error was encountered

Severity: Warning

Message: date() [function.date]: It is not safe to rely on the system's timezone settings. You are *required* to use the date.timezone setting or the date_default_timezone_set() function. In case you used any of those methods and you are still getting this warning, you most likely misspelled the timezone identifier. We selected 'Asia/Krasnoyarsk' for '+07/7.0/no DST' instead

Filename: libraries/Log.php

Line Number: 86

 

hệ quản trị CSDL quan hệ

 

A: Relational database management system – RDBMS

 


 

(cg. cơ sở dữ liệu quan hệ), một chương trình quản lý cơ sở dữ liệu quan hệ có kèm theo tất cả các chương trình phụ trợ cần thiết, các công cụ lập trình và các tài liệu để xây dựng, cài đặt và hiệu chỉnh các ứng dụng về cơ sở dữ liệu theo yêu cầu. Hệ quản trị CSDL có khả năng truy cập dữ liệu được tổ chức thành các tệp dạng bảng và được liên kết với nhau bởi một trường thuộc tính chung.

 

Một RDBMS có khả năng kết hợp các trường dữ liệu từ các tệp khác nhau, cung cấp những công cụ rất hữu ích cho xử lí dữ liệu. Bất kỳ yếu tố dữ liệu nào cũng có thể được tìm thấy nếu biết tên của bảng, tên thuộc tính  và giá trị của khoá chính. Mô hình CSDL quan hệ được đề xuất vào năm 1970 và trở thành hệ quản trị CSDL thông dụng nhất hiện nay.

 

Xt : liên kết, khoá liên kết, liên kết quan hệ

A PHP Error was encountered

Severity: Warning

Message: date() [function.date]: It is not safe to rely on the system's timezone settings. You are *required* to use the date.timezone setting or the date_default_timezone_set() function. In case you used any of those methods and you are still getting this warning, you most likely misspelled the timezone identifier. We selected 'Asia/Krasnoyarsk' for '+07/7.0/no DST' instead

Filename: libraries/Log.php

Line Number: 86

A PHP Error was encountered

Severity: Warning

Message: date() [function.date]: It is not safe to rely on the system's timezone settings. You are *required* to use the date.timezone setting or the date_default_timezone_set() function. In case you used any of those methods and you are still getting this warning, you most likely misspelled the timezone identifier. We selected 'Asia/Krasnoyarsk' for '+07/7.0/no DST' instead

Filename: libraries/Log.php

Line Number: 86