README.md

cel2sql

cel2sql converts CEL (Common Expression Language) to SQL condition. It is specifically targeting BigQuery standard SQL.

Usage

import (
    "context"
    "fmt"
    
    "cloud.google.com/go/bigquery"
    "github.com/cockscomb/cel2sql"
    "github.com/cockscomb/cel2sql/bq"
    "github.com/cockscomb/cel2sql/sqltypes"
    "github.com/google/cel-go/cel"
    "github.com/google/cel-go/checker/decls"
)

// BigQuery table metadata
var client *bigquery.Client = ...
tableMetadata, _ := client.Dataset("your_dataset").Table("employees").Metadata(context.TODO())

// Prepare CEL environment
env, _ := cel.NewEnv(
    cel.CustomTypeProvider(bq.NewTypeProvider(map[string]bigquery.Schema{
        "Employee": tableMetadata.Schema,
    })),
    sqltypes.SQLTypeDeclarations,
    cel.Declarations(
        decls.NewVar("employee", decls.NewObjectType("Employee")),
    ),
)

// Convert CEL to SQL
ast, _ := env.Compile(`employee.name == "John Doe" && employee.hired_at >= current_timestamp() - duration("24h")`)
sqlCondition, _ := cel2sql.Convert(ast)

fmt.Println(sqlCondition) // `employee`.`name` = "John Doe" AND `employee`.`hired_at` >= TIMESTAMP_SUB(CURRENT_TIMESTAMP(), INTERVAL 1 DAY)

Type Conversion

CEL Type	BigQuery Standard SQL Data Type
int	INT64
uint	Unsupported but treated as INT64
double	FLOAT64
bool	BOOL
string	STRING
bytes	BYTES
list	ARRAY
map	STRUCT
null_type	NULL
timestamp	TIMESTAMP
duration	INTERVAL

Supported CEL Operators/Functions

Symbol	Type	SQL
!_	(bool) -> bool	NOT bool
-_	(int) -> int	-int
	(double) -> double	-double
_!=_	(A, A) -> bool	A != A
	(bool, bool) -> bool	bool IS NOT bool
	(A, null) -> bool	A IS NOT NULL
_%_	(int, int) -> int	MOD(int, int)
_&&_	(bool, bool) -> bool	bool AND bool
_*_	(int, int) -> int	int * int
	(double, double) -> double	double * double
_+_	(int, int) -> int	int + int
	(double, double) -> double	double + double
	(string, string) -> string	string || string
	(bytes, bytes) -> bytes	bytes || bytes
	(list(A), list(A)) -> list(A)	list(A) || list(A)
	(google.protobuf.Timestamp, google.protobuf.Duration) -> google.protobuf.Timestamp	TIMESTAMP_ADD(timestamp, INTERVAL duration date_part)
	(google.protobuf.Duration, google.protobuf.Timestamp) -> google.protobuf.Timestamp	TIMESTAMP_ADD(timestamp, INTERVAL duration date_part)
_-_	(int, int) -> int	int - int
	(double, double) -> double	double - double
	(google.protobuf.Timestamp, google.protobuf.Duration) -> google.protobuf.Timestamp	TIMESTAMP_SUB(timestamp, INTERVAL duration date_part)
_/_	(int, int) -> int	int / int
	(double, double) -> double	double / double
_<=_	(bool, bool) -> bool	bool <= bool
	(int, int) -> bool	int <= int
	(double, double) -> bool	double <= double
	(string, string) -> bool	string <= string
	(bytes, bytes) -> bool	bytes <= bytes
	(google.protobuf.Timestamp, google.protobuf.Timestamp) -> bool	timestamp <= timestamp
_<_	(bool, bool) -> bool	bool < bool
	(int, int) -> bool	int < int
	(double, double) -> bool	double < double
	(string, string) -> bool	string < string
	(bytes, bytes) -> bool	bytes < bytes
	(google.protobuf.Timestamp, google.protobuf.Timestamp) -> bool	timestamp < timestamp
_==_	(A, A) -> bool	A = A
	(bool, bool) -> bool	A IS A
	(A, null) -> bool	A IS NULL
_>=_	(bool, bool) -> bool	bool >= bool
	(int, int) -> bool	int >= int
	(double, double) -> bool	double >= double
	(string, string) -> bool	string >= string
	(bytes, bytes) -> bool	bytes >= bytes
	(google.protobuf.Timestamp, google.protobuf.Timestamp) -> bool	timestamp >= timestamp
_>_	(bool, bool) -> bool	bool > bool
	(int, int) -> bool	int > int
	(double, double) -> bool	double > double
	(string, string) -> bool	string > string
	(bytes, bytes) -> bool	bytes > bytes
	(google.protobuf.Timestamp, google.protobuf.Timestamp) -> bool	timestamp > timestamp
_?_:_	(bool, A, A) -> A	IF(bool, A, A)
_[_]	(list(A), int) -> A	list[OFFSET(int)]
	(map(A, B), A) -> B	map.`A`
in	(A, list(A)) -> bool	A IN UNNEST(list)
_||_	(bool, bool) -> bool	bool OR bool
bool	(int) -> bool	CAST(int AS BOOL)
	(string) -> bool	CAST(string AS BOOL)
bytes	(string) -> bytes	CAST(stringAS BYTES)
contains	string.(string) -> bool	INSTR(string, string) != 0
double	(int) -> double	CAST(int AS FLOAT64)
	(string) -> double	CAST(string AS FLOAT64)
duration	(string) -> google.protobuf.Duration	INTERVAL duration date_part
endsWith	string.(string) -> bool	ENDS_WITH(string, string)
getDate	google.protobuf.Timestamp.() -> int	EXTRACT(DAY FROM timestamp)
	google.protobuf.Timestamp.(string) -> int	EXTRACT(DAY FROM timestamp AT string)
getDayOfMonth	google.protobuf.Timestamp.() -> int	EXTRACT(DAY FROM timestamp) - 1
	google.protobuf.Timestamp.(string) -> int	EXTRACT(DAY FROM timestamp AT string) - 1
getDayOfWeek	google.protobuf.Timestamp.() -> int	EXTRACT(DAYOFWEEK FROM timestamp) - 1
	google.protobuf.Timestamp.(string) -> int	EXTRACT(DAYOFWEEK FROM timestamp AT string) - 1
getDayOfYear	google.protobuf.Timestamp.() -> int	EXTRACT(DAYOFYEAR FROM timestamp) - 1
	google.protobuf.Timestamp.(string) -> int	EXTRACT(DAYOFYEAR FROM timestamp AT string) - 1
getFullYear	google.protobuf.Timestamp.() -> int	EXTRACT(YEAR FROM timestamp)
	google.protobuf.Timestamp.(string) -> int	EXTRACT(YEAR FROM timestamp AT string)
getHours	google.protobuf.Timestamp.() -> int	EXTRACT(HOUR FROM timestamp)
	google.protobuf.Timestamp.(string) -> int	EXTRACT(HOUR FROM timestamp AT string)
getMilliseconds	google.protobuf.Timestamp.() -> int	EXTRACT(MILLISECOND FROM timestamp)
	google.protobuf.Timestamp.(string) -> int	EXTRACT(MILLISECOND FROM timestamp AT string)
getMinutes	google.protobuf.Timestamp.() -> int	EXTRACT(MINUTE FROM timestamp)
	google.protobuf.Timestamp.(string) -> int	EXTRACT(MINUTE FROM timestamp AT string)
getMonth	google.protobuf.Timestamp.() -> int	EXTRACT(MONTH FROM timestamp) - 1
	google.protobuf.Timestamp.(string) -> int	EXTRACT(MONTH FROM timestamp AT string) - 1
getSeconds	google.protobuf.Timestamp.() -> int	EXTRACT(SECOND FROM timestamp)
	google.protobuf.Timestamp.(string) -> int	EXTRACT(SECOND FROM timestamp AT string)
int	(bool) -> int	CAST(bool AS INT64)
	(double) -> int	CAST(double AS INT64)
	(string) -> int	CAST(string AS INT64)
	(google.protobuf.Timestamp) -> int	UNIX_SECONDS(timestamp)
matches	string.(string) -> bool	REGEXP_CONTAINS(string, string)
size	(string) -> int	CHAR_LENGTH(string)
	(bytes) -> int	BYTE_LENGTH(bytes)
	(list(A)) -> int	ARRAY_LENGTH(list)
startsWith	string.(string) -> bool	STARTS_WITHstring, string)
string	(bool) -> string	CAST(bool AS STRING)
	(int) -> string	CAST(int AS STRING)
	(double) -> string	CAST(double AS STRING)
	(bytes) -> string	CAST(bytes AS STRING)
	(timestamp) -> string	CAST(timestamp AS STRING)
timestamp	(string) -> google.protobuf.Timestamp	TIMESTAMP(string)

Standard SQL Types/Functions

cel2sql supports time related types bellow.

• DATE
• TIME
• DATETIME

cel2sql contains time related functions bellow.

• current_date()
• current_time()
• current_datetime()
• current_timestamp()
• interval(N, date_part)