TreSQL

TreSQL (Tree SQL)

Mārtiņš Rumovskis

Agenda

Motivation

TreSQL vs SQL

TreSQL statement structure

Scala API

Old Good SQL

Traditionally we can get data in the tabular form DEPTNO DNAME LOC

30 SALES Chicago

Old Good SQL

But we need something like this...

Traditionally we can get data in the tabular form DEPTNO DNAME LOC

30 SALES Chicago

DEPTNO DNAME LOC EMPNO ENAME

30 SALES Chicago 1 ALLEN

2 WARD

3 MARTIN

20 RESEARCH Dallas 4 MILLER

5 SCOTT

Old Good SQL

But we need somethink like this...

Traditionally we can get data in the tabular form

Or like this...

DEPTNO DNAME LOC EMPNO ENAME

30 SALES Chicago 1 ALLEN

2 WARD

3 MARTIN

20 RESEARCH Dallas 4 MILLER

5 SCOTT

DEPTNO DNAME LOC

30 SALES Chicago

NAME DRIVER_LIC LANGUAGES

SCOTT A,B EN,LV,RU

MILLER B,C EN,IT

Old Good SQL (Cont)

We need to write joins

select * from emp e join dept d on e.deptno = d.deptno

Old Good SQL (Cont)

We need to write joins

Explicitly specify id column name

select * from emp e join dept d on e.deptno = d.deptno

select * from dept where id in (10, 20, 30)

Problems of JDBC

JDBC

We need to do SQL to Java mappings

...well you know

We need to bind every variable in the SQL statement noted as

‘?’ otherwise exception occurs

setXXX(idx, value)

Problems of JDBC

JDBC

We need to do SQL to Java mappings

...well you know

We cannot run several queries

setXXX(idx, value)

select * from dept where deptno = 10,

select * from emp where job = 'MGR'

What’s about ORM?

ORM (Hibernate)

We need to define class model and mapping

What’s about ORM?

ORM (Hibernate)

We need to define class model and mapping

And we still need SQL (for advanced use)

Agenda

Motivation

TreSQL vs SQL


Scala API

Sql vs TreSQL

Simple SQL

SQL: select * from dept

Sql vs TreSQL


TreSQL: dept

Simple SQL

Sql vs TreSQL

SQL: select * from dept where deptno = 10

Select... Where

Sql vs TreSQL


TreSQL: dept[10]

Select... Where

Sql vs TreSQL

More complex select

SQL: select deptno, dname from dept

select ename from emp where deptno = :deptno

Sql vs TreSQL

More complex select (needs programming when using

SQL)

SQL: select deptno, dname from dept

select ename from emp where deptno = :deptno

TreSQL: dept{deptno, dname,

|emp[:1(1) = deptno] {ename} employees}

Sql vs TreSQL

Multiple selects


select * from emp where job = 'MGR'

Sql vs TreSQL

Multiple selects


select * from emp where job = 'MGR‘

TreSQL: dept[10], emp[job = 'MGR']

Sql vs TreSQL

Outer join order by


left join emp on dept.deptno = emp.deptno

order by dname

Sql vs TreSQL

Outer join order by


left join emp on dept.deptno = emp.deptno

order by dname

TreSQL: dept/emp? #(dname)

Sql vs TreSQL

In, subselect

SQL: select * from dept where deptno

in (select deptno from emp)

Sql vs TreSQL

In, subselect

SQL: select * from dept where deptno

in (select deptno from emp)

TreSQL: dept [deptno in (emp{deptno})]

Sql vs TreSQL

Exists, correlated subselect

SQL: select * from dept d where

exists select * from emp e

where d.deptno = e.deptno

Sql vs TreSQL

Exists, correlated subselect

SQL: select * from dept d where

exists select * from emp e

where d.deptno = e.deptno

TreSQL: dept d[(emp e[e.deptno = d.deptno])]

Sql vs TreSQL

More complex example (using SQL programming is

needed)

dept{deptno, dname,

|emp[sal >= hisal & sal <= losal]salgrade[deptno =

:1(1)]

{grade, hisal, losal, count(empno) empcount,

|emp/dept[sal >= :1(2) & sal <= :1(3) &

emp.deptno = :2(1)]

{ename, emp.deptno, dname, sal}#(empno) emps

} (grade, hisal, losal) #(1) salgrades

} #(deptno)

Agenda

Motivation

TreSQL vs SQL


Scala API

TreSQL Language Structure

SELECT statement structure

<from>[<where>][<columns>][<group by>

[<having>]][<order>][<offset> [<limit>]]

table1[join cond]table2[where]{columns} (group

cols)^(having expr) #(order) (offset limit)


INSERT

Statement structure

DEPT {DEPTNO, DNAME, LOC}

+ [10, "ACCOUNTING", "NEW YORK"]

table {col1, col2} + [val1, val2]


UPDATE

Statement structure

emp[1] {ENAME, JOB, MGR, HIREDATE, SAL, COMM, DEPTNO} =

[?, ?, ?, ?, ?, ?, ?]

table [where] {col1, col2} = [val1, val2]


DELETE

Statement structure

emp - [1]

table - [where]

Agenda

Motivation

TreSQL vs SQL


Scala API

Scala API

Code example:

import org.tresql._

Env update connection

Query.foreach("dept[?]{dname}", 10) {row=> println(row(0))}

//

val expr = Query.build("emp[deptno = ?]{*}")

val result = expr.select(10)

result foreach println

expr close

Jsonizer.jsonize(Query(expr, pars), writer, rType)

Scala API

Code example:

import org.tresql._



//




expr close

org.tresql.Env Expression execution environment. Used for setting

database connection.

Scala API

Code example:

import org.tresql._



//




expr close

org.tresql.Query

Expression execution, result iteration

Scala API

Code example:

import org.tresql._



//




expr close

org.tresql.Expr

Builded expression. Equivalent to java.sql.PreparedStatement

Scala API

Code example:

import org.tresql._



//




expr close

org.tresql.Expr

Expression result – org.tresql.Result

Scala API

Code example:

import org.tresql._

org.tresql.Env update connection

org.tresql.Query.foreach("dept[?]{dname}", 10) {row=> println(row(0))}

//




expr close

Jsonizer.jsonize(Query(expr, pars), writer, rType)

org.tresql.Expr

Result JSON formatting

Scala API

Code example:

import org.tresql._

org.tresql.Env update connection

org.tresql.Query.foreach("emp[sal > ? & deptno = ?]", 1000, 10) {row=>

println(row(0))}

org.tresql.Query.foreach("emp[sal > ? & deptno = ?]", 1000) {row=>

println(row(0))}

org.tresql.Expr

Optional binding

That’s about it!

Visit: https://github.com/mrumkovskis/Query

TreSQL

Technology

Transcript of TreSQL