Background
Default value is commonly used in data input. With it, some fields of newly added record can be generated automatically. Sometimes it is for the convenience of users. Sometimes, it is used when users aren't allowed to input these fields.
Sequential number is a particular case of default value. It has a steady increment or decrement, while complex default values don't have this rule.

Difficulty
For an input interface without dynamic addition and deletion, it may be not very difficult to realize default value/sequential number.
However, for an input interface with dynamic addition or deletion, it will be very difficult, especially for sequential number.
One of the most important characteristics of sequential number is that it is non-repetitive. But under B/S mode, in the condition of concurrent access, users’ browsers don't need to interact with server for addition or deletion of row. Otherwise, the interaction cost is too must huge. Therefore, it is very difficult to keep sequential number non-repetitive in every browser in B/S mode.

Solution
For users' convenience, RAQ Report provides thoughtful function of default value/sequential number. With RAQ Report, client-side browser can dynamically compute the starting value of sequential number by expression, and realize perfect sequential number function through flexible rules of steady increment or decrement.

Easy Operation
1. Set Report style as Row report and set Input type as Input Report.
2. Write starting value expression and define rules for steady increment or decrement.

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