[Enhance] Add "statistics" meta table and fix some mysql compatibility problem

[FlowerSaid]

… the return type of method ‘str_to_date’ to the actual type datetime;3,In the header information returned by mysql, the data type length is returned according to the actual type.

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[morningman]

Remove author name, it is not necessary

[morningman]

Suggested change

	public boolean getTimeType() {
	public boolean isTimeType() {

[morningman]

LGTM