官术网_书友最值得收藏!

Conventions

In this book, you will find a number of text styles that distinguish between different kinds of information. Here are some examples of these styles and an explanation of their meaning.

Code words in text, database table names, folder names, filenames, file extensions, pathnames, dummy URLs, user input, and Twitter handles are shown as follows: "If any of the checks fail, you should do ROLLBACK instead of COMMIT."

A block of code is set as follows:

CREATE TABLE accounts(owner text, balance numeric, amount numeric);
INSERT INTO accounts VALUES ('Bob',100);
INSERT INTO accounts VALUES ('Mary',200);

When we wish to draw your attention to a particular part of a code block, the relevant lines or items are set in bold:

CREATE OR REPLACE FUNCTION fibonacci_seq(num integer)
 RETURNS SETOF integer AS $$
DECLARE
  a int := 0;
  b int := 1;
BEGIN
  IF (num <= 0)
    THEN RETURN;
  END IF;

  RETURN NEXT a;
  LOOP
    EXIT WHEN num <= 1;
    RETURN NEXT b;

      num = num - 1;
      SELECT b, a + b INTO a, b;
  END LOOP;
END;
$$ LANGUAGE plpgsql;

Any command-line input or output is written as follows:

$ psql -c "SELECT 1 AS test"

New terms and important words are shown in bold. Words that you see on the screen, for example, in menus or dialog boxes, appear in the text like this: "Enter some values into the columns, as seen in the preceding screenshot, and click on the Debug button."

Note

Warnings or important notes appear in a box like this.

Tip

Tips and tricks appear like this.

主站蜘蛛池模板: 云浮市| 祁阳县| 保山市| 黄平县| 如皋市| 岳池县| 广灵县| 驻马店市| 台湾省| 如东县| 遂溪县| 崇礼县| 商河县| 临泽县| 多伦县| 济南市| 岑溪市| 呈贡县| 安新县| 天台县| 郸城县| 青岛市| 蒙城县| 平阳县| 商城县| 安陆市| 上饶县| 阿克陶县| 丹阳市| 新郑市| 抚顺市| 墨江| 独山县| 新民市| 称多县| 福州市| 紫阳县| 武汉市| 望都县| 平潭县| 喜德县|