| Informix Guide to SQL: Syntax Introduction |
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This section describes the conventions that this manual uses. These conventions make it easier to gather information from this and other volumes in the documentation set.
The following conventions are discussed:
This manual uses the following conventions to introduce new terms, illustrate screen displays, describe command syntax, and so forth.
Tip: When you are instructed to "enter" characters or to "execute" a command, immediately press RETURN after the entry. When you are instructed to "type" the text or to "press" other keys, no RETURN is required.
Icon Conventions
Throughout the documentation, you will find text that is identified by several different types of icons. This section describes these icons.
Comment icons identify three types of information, as the following table describes. This information always appears in italics.
Feature, product, and platform icons identify paragraphs that contain feature-specific, product-specific, or platform-specific information.
These icons can apply to an entire section or to one or more paragraphs within a section. If an icon appears next to a section heading, the information that applies to the indicated feature, product, or platform ends at the next heading at the same or higher level. A 
symbol indicates the end of feature-, product-, or platform-specific information that appears in one or more paragraphs within a section.
Compliance icons indicate paragraphs that provide guidelines for complying with a standard.
These icons can apply to an entire section or to one or more paragraphs within a section. If an icon appears next to a section heading, the information that applies to the indicated feature, product, or platform ends at the next heading at the same or higher level. A symbol indicates the end of feature-, product-, or platform-specific information that appears within one or more paragraphs within a section.
This section describes conventions for syntax diagrams. Each diagram displays the sequences of required and optional keywords, terms, and symbols that are valid in a given statement or segment, as Figure 1 shows.
Each syntax diagram begins at the upper-left corner and ends at the upper-right corner with a vertical terminator. Between these points, any path that does not stop or reverse direction describes a possible form of the statement.
Syntax elements in a path represent terms, keywords, symbols, and segments that can appear in your statement. The path always approaches elements from the left and continues to the right, except in the case of separators in loops. For separators in loops, the path approaches counterclockwise. Unless otherwise noted, at least one blank character separates syntax elements.
You might encounter one or more of the following elements on a path.
Figure 2 shows a syntax diagram that uses most of the path elements that the previous table lists.
To use this diagram to construct a statement, start at the top left with the keyword DELETE FROM. Follow the diagram to the right, proceeding through the options that you want.
Figure 2 illustrates the following steps:
Examples of SQL code occur throughout this manual. Except where noted, the code is not specific to any single Informix application development tool. If only SQL statements are listed in the example, they are not delimited by semicolons. For instance, you might see the code in the following example:
To use this SQL code for a specific product, you must apply the syntax rules for that product. For example, if you are using DB-Access, you must delimit multiple statements with semicolons. If you are using an SQL API, you must use EXEC SQL at the start of each statement and a semicolon (or other appropriate delimiter) at the end of the statement.
Tip: Ellipsis points in a code example indicate that more code would be added in a full application, but it is not necessary to show it to describe the concept being discussed.
For detailed directions on using SQL statements for a particular application development tool or SQL API, see the manual for your product.
) on a path indicates that you can only use that path the indicated number of times, even if it is part of a larger loop. You can specify size no more than three times within this statement segment.
