[summary]
1. complete single-table syntax, add delete options and parition.
2. add support to parse multi-table syntax.
3. add support to delete without where clause, like "delete from t1
limit 2"

[test case]
sqlparser/ast_test.go
sqlparser/parse_test.go
sqlparser/ast_test.go
src/planner/builder/expr_test.go
src/planner/delete_plan_test.go

[patch codecov]
sqlparser/ast.go 96.1%
sqlparser/ast_funcs.go 94.4%
src/planner/delete_plan.go  93.9%
src/planner/update_plan.go  95.1%

[summary]
1. complete single-table syntax, add delete options and parition.
2. add support to parse multi-table syntax.
3. add support to delete without where clause, like "delete from t1
limit 2"

[test case]
sqlparser/ast_test.go
sqlparser/parse_test.go
sqlparser/ast_test.go
src/planner/builder/expr_test.go
src/planner/delete_plan_test.go

[patch codecov]
sqlparser/ast.go 96.1%
sqlparser/ast_funcs.go 94.4%
src/planner/delete_plan.go  93.9%
src/planner/update_plan.go  95.1%

[summary]
add more test to improve the codecov of queryz.go and delete_plan.go

[test case]
src/backend/queryz_test.go
src/planner/delete_plan_test.go

[patch codecov]
src/backend/queryz.go 96.3%
src/planner/delete_plan.go 95.9%

[summary]
add more test to improve the codecov of queryz.go and delete_plan.go

[test case]
src/backend/queryz_test.go
src/planner/delete_plan_test.go

[patch codecov]
src/backend/queryz.go 96.3%
src/planner/delete_plan.go 95.9%

[summary]
1. complete single-table syntax, add delete options and parition.
2. add support to parse multi-table syntax.
3. add support to delete without where clause, like "delete from t1
limit 2"

[test case]
sqlparser/ast_test.go
sqlparser/parse_test.go
sqlparser/ast_test.go
src/planner/builder/expr_test.go
src/planner/delete_plan_test.go

[patch codecov]
sqlparser/ast.go 96.1%
sqlparser/ast_funcs.go 94.4%
src/planner/delete_plan.go  93.9%
src/planner/update_plan.go  95.1%

[summary]
add more test to improve the codecov of queryz.go and delete_plan.go

[test case]
src/backend/queryz_test.go
src/planner/delete_plan_test.go

[patch codecov]
src/backend/queryz.go 96.3%
src/planner/delete_plan.go 95.9%

[summary]
1. complete single-table syntax, add delete options and parition.
2. add support to parse multi-table syntax.
3. add support to delete without where clause, like "delete from t1
limit 2"

[test case]
sqlparser/ast_test.go
sqlparser/parse_test.go
sqlparser/ast_test.go
src/planner/builder/expr_test.go
src/planner/delete_plan_test.go

[patch codecov]
sqlparser/ast.go 96.1%
sqlparser/ast_funcs.go 94.4%
src/planner/delete_plan.go  93.9%
src/planner/update_plan.go  95.1%

[summary]
add more test to improve the codecov of queryz.go and delete_plan.go

[test case]
src/backend/queryz_test.go
src/planner/delete_plan_test.go

[patch codecov]
src/backend/queryz.go 96.3%
src/planner/delete_plan.go 95.9%

[summary]
1. add checkField() function to check the column field illegal or not if
the delete statment has field in where | order by clause.
e.g.:
mysql> delete from t where x.a=1;
ERROR 1054 (42S22): Unknown column 'x.a' in 'where clause'
mysql> delete from t where t.a=1 order by xx.a;
ERROR 1054 (42S22): Unknown column 'xx.a' in 'order clause'

2. add rewriteField() function to rewrite the column field in where | order by clause.
e.g.:
delete from t where a=1;
after rewrite maybe:
delete from test.t_0001 where test.t_0001.a=1;

[test case]
src/planner/delete_plan_test.go

[patch codecov]
src/planner/common.go  95.8%
src/planner/delete_plan.go 96.2%

[summary]
1. add checkField() function to check the column field illegal or not if
the delete statment has field in where | order by clause.
e.g.:
mysql> delete from t where x.a=1;
ERROR 1054 (42S22): Unknown column 'x.a' in 'where clause'
mysql> delete from t where t.a=1 order by xx.a;
ERROR 1054 (42S22): Unknown column 'xx.a' in 'order clause'

2. add rewriteField() function to rewrite the column field in where | order by clause.
e.g.:
delete from t where a=1;
after rewrite maybe:
delete from test.t_0001 where test.t_0001.a=1;

[test case]
src/planner/delete_plan_test.go

[patch codecov]
src/planner/common.go  95.8%
src/planner/delete_plan.go 96.2%

[summary]
fix some comments error and code format radondb#713

[test case]
N/A

[patch codecov]
N/A

…ent_#713

*.: complete delete syntax #713