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)