Appendix 1: Command Line Options
CQL has a variety of command line (CLI) options but many of them are only interesting for cql development. Nonetheless this is a comprehensive list:
- note CQL is often used after the c pre-processor is run so this kind of invocation is typical:
cc -E -x c foo.sql | cql [args]
With No Optionsβ
- emits a usage message
--in fileβ
- reads the given file for the input instead of stdin
- the input should probably have already been run through the C pre-processor as above
- returns non-zero if the file fails to parse
Example:
cql --in test.sql
--semβ
- performs semantic analysis on the input file ONLY
- the return code is zero if there are no errors
Example:
cql --in sem_test.sql --sem
--astβ
- walks the AST and prints it to stdout in human readable text form
- may be combined with --sem (semantic info will be included) Example
cql --in sem_test.sql --sem --ast >sem_ast.out
--echoβ
- walks the AST and emits the text of a program that would create it
- this has the effect of "beautifying" badly formatted input or "canonicalizing" it
- some sensible indenting is added but it might not be the original indenting
- extraneous whitespace, parens, etc. are removed
- may be combined with --sem (in which case you see the source after any rewrites for sugar)
- this also validates that the input can be parsed
Example
cql --in test.sql --echo >test.out # test.out is "equivalent" to test.sql
--dotβ
- prints the internal AST to stdout in DOT format for graph visualization
- this is really only interesting for small graphs for discussion as it rapidly gets insane
Example:
cql --dot --in dottest.sql
--cg output1 output2 ...β
- any number of output files may be needed for a particular result type, two is common
- the return code is zero if there are no errors
- any --cg option implies --sem
Example:
cql --in foo.sql --cg foo.h foo.c
--nolinesβ
- Suppress the # directives for lines. Useful if you need to debug the C code.
Example:
cql --in test.sql --nolines --cg foo.h foo.c
--global_proc nameβ
- any loose SQL statements not in a stored proc are gathered and put into a procedure of the given name
- when generating a schema migrate script the global proc name is used as a prefix on all of the artifacts so that there can be several independent migrations linked into a single executable
--compressβ
- for use with the C result type, (or any similar types added to the runtime array in your compiler)
- string literals for the SQL are broken into "fragments" the DML is then represented by an array of fragments
- since DML is often very similar there is a lot of token sharing possible
- the original string is recreated at runtime from the fragments and then executed
- comments show the original string inline for easier debugging and searching
NOTE: different result types require a different number of output files with different meanings
--testβ
- some of the output types can include extra diagnostics if
--test
is included - the test output often makes the outputs badly formed so this is generally good for humans only
--devβ
- some codegen features only make sense during development, this enables dev mode to turn those one ** example: explain query plan
--c_include_namespaceβ
- for the C codegen runtimes, it determines the header namespace (as in #include "namespace/file.h") that goes into the output C file
- if this option is used, it is prefixed to the first argment to --cg to form the include path in the C file
- if absent there is no "namespace/" prefix
--c_include_pathβ
- for the C codegen runtimes, it determines the full header path (as in #include "your_arg") that goes into the output C file
- if this option is used, the first argment to --cg controls only the output path and does not appear in include path at all
- this form overrides --c_include_namespace if both are specified
--objc_c_include_pathβ
- for ObjC codegen runtimes that need to refer to the generated C code, this represents the header of the C generated code that will be used during inclusion from the ObjC file
Result Types (--rt *)β
These are the various outputs the compiler can produce.
--rt cβ
- requires two output files (foo.h and foo.c)
- this is the standard C compilation of the sql file
--cqlrt foo.hβ
- emits
#include "foo.h"
into the C output instead of#include "cqlrt.h"
--generate_type_gettersβ
- changes C output for CQL result sets so that the field readers used shared functions to get fields of a certain type
- this style of codegen makes result-sets more interoperable with each other if they have similar shape so it can be useful
--generate_exportsβ
- adds an additional output file
- example: `--in foo.sql --generate_exports --rt c --cg foo.h foo.c foo_exports.sql
- the output file
foo_exports.sql
includes procedure declarations for the contents offoo.sql
- basically automatically generates the CQL header file you need to access the procedures in the input from some other file
- if it were C it would be like auto-generating
foo.h
fromfoo.c
--rt objcβ
- objective C wrappers for result sets produced by the stored procedures in the input
- these depend on the output of a standard codegen run so this is additive
- requires one output file (foo.h)
--rt schemaβ
- produces the canonical schema for the given input files
- stored procedures etc. are removed
- whitespace etc. is removed
- suitable for use to create the next or first "previous" schema for schema validation
- requires one output file
--rt schema_upgradeβ
- produces a CQL schema upgrade script which can then be compiled with CQL itself
- see the chapter on schema upgrade/migration: Chapter 10
- requires one output file (foo.sql)
--include_regions a b cβ
- the indicated regions will be declared
- used with
--rt schema_upgrade
or--rt schema
- in the upgrade case excluded regions will not be themselves upgraded, but may be referred, to by things that are being upgraded
--exclude_regions x y zβ
- the indicated regions will still be declared but the upgrade code will be suppressed, the presumption being that a different script already upgrades x y z
- used with
--rt schema_upgrade
--min_schema_version nβ
- the schema upgrade script will not include upgrade steps for schema older than the version specified
--schema_exclusiveβ
- the schema upgrade script assumes it owns all the schema in the database, it aggressively removes other things
--rt json_schemaβ
- produces JSON output suitable for consumption by downstream codegen
- the JSON includes a definition of the various entities in the input
- see the section on JSON output for details
--rt query_planβ
- produces CQL output which can be re-compiled by CQL as normal input
- the output consists of a set of procedures that will emit all query plans for the DML that was in the input
- see also
--rt udf
and Chapter 15
--rt statsβ
- produces a simple .csv file with node count information for AST nodes per procedure in the input
- requires one output file (foo.csv)
--rt udfβ
- produces stub UDF implementations for all UDFS that were seen in the input
- this output is suitable for use with
--rt query_plan
so that SQL with UDFs will run in a simple context - requires two output files (e.g. udfs.h and udfs.c)
- See also Chapter 15