说明
=========
该项目为mysql sql解析器，词法分析和语法分析基于oceanbase 0.4版本，新写sql优化以及根据本地化处理原则和数据路由生成执行计划。
整体过程如下：
编译：
STEP1：$ sh gen_parser.sh
STEP2: $ make
执行： $ ./sql_parser
select join语句如下时，解析后的语法树：
$ ./sql_parser.exe
<<Part 1 : SQL STRING>> SELECT tt.id, tt.name, pp.age FROM tt JOIN pp ON tt.id = pp.id where tt.id = 100 ORDER BY tt.name
<<Part 2 : PARSE TREE>>
|-T_STMT_LIST
|-T_SELECT
|-NULL
|-T_PROJECT_LIST
|-T_PROJECT_STRING
|-T_OP_NAME_FIELD
|-T_IDENT : tt
|-T_IDENT : id
|-T_PROJECT_STRING
|-T_OP_NAME_FIELD
|-T_IDENT : tt
|-T_IDENT : name
|-T_PROJECT_STRING
|-T_OP_NAME_FIELD
|-T_IDENT : pp
|-T_IDENT : age
|-T_FROM_LIST
|-T_JOINED_TABLE
|-T_JOIN_INNER
|-T_IDENT : tt
|-T_IDENT : pp
|-T_OP_EQ
|-T_OP_NAME_FIELD
|-T_IDENT : tt
|-T_IDENT : id
|-T_OP_NAME_FIELD
|-T_IDENT : pp
|-T_IDENT : id
|-T_OP_EQ
|-T_OP_NAME_FIELD
|-T_IDENT : tt
|-T_IDENT : id
|-T_INT : 100
|-NULL
|-NULL
|-NULL
|-NULL
|-NULL
|-NULL
|-T_SORT_LIST
|-T_SORT_KEY
|-T_OP_NAME_FIELD
|-T_IDENT : tt
|-T_IDENT : name
|-T_SORT_ASC
|-NULL
|-NULL
|-NULL
<<Part 3 : LOGICAL PLAN>>
<LogicalPlan>
<StmtList>
ObSelectStmt 0 Begin
<TableItemList Begin>
{Num 0, TableId:1, TableName:tt, AliasName:NULL, Type:BASE_TABLE, RefId: 1}
{Num 1, TableId:2, TableName:pp, AliasName:NULL, Type:BASE_TABLE, RefId: 2}
<TableItemList End>
<ColumnItemList Begin>
{Num 0, ColumnId:1, ColumnName:id, TableRef:1}
{Num 1, ColumnId:6, ColumnName:id, TableRef:2}
{Num 2, ColumnId:2, ColumnName:name, TableRef:1}
{Num 3, ColumnId:8, ColumnName:age, TableRef:2}
<ColumnItemList End>
WHERE ::= <5>
SELECT ::= <2, id>, <3, name>, <4, age>
FROM ::= <1> INNER JOIN <2> ON <1>
ORDER BY ::= <6, ASC>
ObSelectStmt 0 End
</StmtList>
<ExprList>
<ObSqlRawExpr 0 Begin>
expr_id = 1
(table_id : column_id) = (NULL : 65519)
ObBinaryOpRawExpr
T_OP_EQ
ObBinaryRefRawExpr
T_REF_COLUMN : [table_id, column_id] = [1, 1]
ObBinaryRefRawExpr
T_REF_COLUMN : [table_id, column_id] = [2, 6]
<ObSqlRawExpr 0 End>
<ObSqlRawExpr 1 Begin>
expr_id = 2
(table_id : column_id) = (NULL : 65518)
ObBinaryRefRawExpr
T_REF_COLUMN : [table_id, column_id] = [1, 1]
<ObSqlRawExpr 1 End>
<ObSqlRawExpr 2 Begin>
expr_id = 3
(table_id : column_id) = (NULL : 65517)
ObBinaryRefRawExpr
T_REF_COLUMN : [table_id, column_id] = [1, 2]
<ObSqlRawExpr 2 End>
<ObSqlRawExpr 3 Begin>
expr_id = 4
(table_id : column_id) = (NULL : 65516)
ObBinaryRefRawExpr
T_REF_COLUMN : [table_id, column_id] = [2, 8]
<ObSqlRawExpr 3 End>
<ObSqlRawExpr 4 Begin>
expr_id = 5
(table_id : column_id) = (NULL : 65515)
ObBinaryOpRawExpr
T_OP_EQ
ObBinaryRefRawExpr
T_REF_COLUMN : [table_id, column_id] = [1, 1]
ObConstRawExpr
T_INT : 100
<ObSqlRawExpr 4 End>
<ObSqlRawExpr 5 Begin>
expr_id = 6
(table_id : column_id) = (1 : 2)
ObBinaryRefRawExpr
T_REF_COLUMN : [table_id, column_id] = [1, 2]
<ObSqlRawExpr 5 End>
</ExprList>
</LogicalPlan>
最终经过tablet定位以及sql重新拼装，最终生成的执行计划为：
I0227 14:07:37 10661 jd_exec_plan.cpp:1712]: exec_plan_unit shard name: tt1
I0227 14:07:37 10661 jd_exec_plan.cpp:1713]: exec_plan_unit SQL name : SELECT tt.id, tt.name, pp.age FROM tt1 AS tt JOIN pp1 AS pp ON tt.id = pp.id WHERE tt.id = 100 ORDER BY tt.name ASC LIMIT 0, 100000000
然后就可以把sql语句发送到相应的分片中去执行。
DATE : 2014.2.26
EMAIL: gqinbo@gmail.com