Builder

It's only a tool helping you build your queries.You should also use the database/sql to operate database

complex sql always need special optimization,which is hard to do it here.So, for very comlex sql, I suggest you write it manually, Exported WhereIn Helper will be added soon

QuickStart

example_1

package main

import (
    "database/sql"
    _ "github.com/go-sql-driver/mysql"
    qb "github.com/didi/gendry/builder"
)

func main() {
    db,err := sql.Open("mysql", "xxxxxxxxxxx")
    if nil != err {
        panic(err)
    }
    mp := map[string]interface{}{
    	"country": "China",
    	"role": "driver",
    	"age >": 45,
        "_groupby": "name",
        "_having": map[string]interface{}{
            "total >": 1000,
            "total <=": 50000,
        },
    	"_orderby": "age desc",
    }
    cond,vals,err := qb.BuildSelect("tableName", where, []string{"name", "count(price) as total", "age"})
    
    //cond: SELECT name,count(price) as total,age FROM tableName WHERE (age>? AND country=? AND role=?) GROUP BY name HAVING (total>? AND total<=?) ORDER BY age DESC
    //vals: []interface{}{45, "China", "driver", 1000, 50000}

	if nil != err {
		panic(err)
	}	
	
    rows,err := db.Query(cond, vals...)
    if nil != err {
        panic(err)
    }
    defer rows.Close()
    for rows.Next() {
        var id int
        var name,phone string
        rows.Scan(&id, &name, &phone)
        fmt.Println(id, name, phone)
    }

    //have fun !!
}

API

BuildSelect

sign: BuildSelect(table string, where map[string]interface{}, field []string) (string,[]interface{},error)

operators supported:

• =
• >
• <
• =
• <=
• >=
• !=
• <>
• in
• like

where := map[string]interface{}{
	"foo <>": "aha",
	"bar <=": 45,
	"sex in": []interface{}{"girl", "boy"},
	"name like": "%James",
}

others supported:

• _orderby
• _groupby
• _having
• _limit

where := map[string]interface{}{
	"age >": 100,
	"_orderby": "fieldName asc",
	"_groupby": "fieldName",
	"_having": map[string]interface{}{"foo":"bar",},
	"_limit": []uint{begin,end},
}

Note:

• _having will be ignored if _groupby isn't setted
• value of _limit could be:
  • "_limit": []uint{a,b} => LIMIT a,b
  • "_limit": []uint{a} => LIMIT 0,a

Aggregate

sign: AggregateQuery(ctx context.Context, db *sql.DB, table string, where map[string]interface{}, aggregate AggregateSymbleBuilder) (ResultResolver, error)

Aggregate is a helper function to help executing some aggregate queries such as:

• sum
• avg
• max
• min
• count

example:

where := map[string]interface{}{
    "score > ": 100,
    "city in": []interface{}{"Beijing", "Shijiazhuang",}
}
// supported: AggregateSum,AggregateMax,AggregateMin,AggregateCount,AggregateAvg
result, err := AggregateQuery(ctx, db, "tableName", where, AggregateSum("age"))
sumAge := result.Int64()

result,err = AggregateQuery(ctx, db, "tableName", where, AggregateCount("*")) 
numberOfRecords := result.Int64()

result,err = AggregateQuery(ctx, db, "tableName", where, AggregateAvg("score"))
averageScore := result.Float64()

BuildUpdate

sign: BuildUpdate(table string, where map[string]interface{}, update map[string]interface{}) (string, []interface{}, error)

BuildUpdate is very likely to BuildSelect but it doesn't support:

• _orderby
• _groupby
• _limit
• _having

where := map[string]interface{}{
	"foo <>": "aha",
	"bar <=": 45,
	"sex in": []interface{}{"girl", "boy"},
}
update := map[string]interface{}{
	"role": "primaryschoolstudent",
	"rank": 5,
}
cond,vals,err := qb.BuildUpdate("table_name", where, update)

db.Exec(cond, vals...)

BuildInsert

sign: BuildInsert(table string, data []map[string]interface{}) (string, []interface{}, error)

data is a slice and every element(map) in it must have the same keys:

var data []map[string]interface{}
data = append(data, map[string]interface{}{
    "name": "deen",
    "age":  23,
})
data = append(data, map[string]interface{}{
    "name": "Tony",
    "age":  30,
})
cond, vals, err := qb.BuildInsert(table, data)
db.Exec(cond, vals...)

NamedQuery

sign: func NamedQuery(sql string, data map[string]interface{}) (string, []interface{}, error)

For very complex query, this might be helpful. And for critical system, this is recommended.

cond, vals, err := builder.NamedQuery("select * from tb where name={{name}} and id in (select uid from anothertable where score in {{m_score}})", map[string]interface{}{
	"name": "caibirdme",
	"m_score": []float64{3.0, 5.8, 7.9},
})

assert.Equal("select * from tb where name=? and id in (select uid from anothertable where score in (?,?,?))", cond)
assert.Equal([]interface{}{"caibirdme", 3.0, 5.8, 7.9}, vals)

BuildDelete

sign: BuildDelete(table string, where map[string]interface{}) (string, []interface{}, error)

Safety

If you use Prepare && stmt.SomeMethods then You have no need to worry about the safety. Prepare is a safety mechanism backed by mysql, it makes sql injection out of work.

So builder doesn't escape the string values it recieved -- it's unnecessary

If you call db.Query(cond, vals...) directly, and you don't set interpolateParams which is one of the driver's variables to true, the driver actually will still prepare a stmt.So it's safe.

Remember:

• don't assemble raw sql yourself,use builder instead.
• don't set interpolateParams to true(default false) if you're not aware of the consequence.

Obey instructions above there's no safety issues for most cases.