From 285be0d7935b5505b6cc1509742f3fc87e19ea09 Mon Sep 17 00:00:00 2001 From: jian he Date: Mon, 9 Feb 2026 11:00:06 +0800 Subject: [PATCH v25 2/4] json format for COPY TO --- doc/src/sgml/ref/copy.sgml | 13 ++-- src/backend/commands/copy.c | 49 ++++++++++---- src/backend/commands/copyto.c | 101 ++++++++++++++++++++++++++--- src/backend/parser/gram.y | 8 +++ src/backend/utils/adt/json.c | 5 +- src/bin/psql/tab-complete.in.c | 2 +- src/include/commands/copy.h | 1 + src/include/utils/json.h | 2 + src/test/regress/expected/copy.out | 78 ++++++++++++++++++++++ src/test/regress/sql/copy.sql | 48 ++++++++++++++ 10 files changed, 278 insertions(+), 29 deletions(-) diff --git a/doc/src/sgml/ref/copy.sgml b/doc/src/sgml/ref/copy.sgml index 0ad890ef95f..75f55bbf6f8 100644 --- a/doc/src/sgml/ref/copy.sgml +++ b/doc/src/sgml/ref/copy.sgml @@ -228,10 +228,15 @@ COPY { table_name [ ( text, csv (Comma Separated Values), + json (JavaScript Object Notation), or binary. The default is text. See below for details. + + The json option is allowed only in + COPY TO. + @@ -266,7 +271,7 @@ COPY { table_name [ ( CSV format. This must be a single one-byte character. - This option is not allowed when using binary format. + This option is not allowed when using binary or json format. @@ -280,7 +285,7 @@ COPY { table_name [ ( CSV format. You might prefer an empty string even in text format for cases where you don't want to distinguish nulls from empty strings. - This option is not allowed when using binary format. + This option is not allowed when using binary or json format. @@ -303,7 +308,7 @@ COPY { table_name [ ( COPY FROM, and only when - not using binary format. + not using binary or json format. @@ -330,7 +335,7 @@ COPY { table_name [ ( COPY FROM commands. - This option is not allowed when using binary format. + This option is not allowed when using binary or json format. diff --git a/src/backend/commands/copy.c b/src/backend/commands/copy.c index 2f46be516f2..29c121c7f08 100644 --- a/src/backend/commands/copy.c +++ b/src/backend/commands/copy.c @@ -597,6 +597,8 @@ ProcessCopyOptions(ParseState *pstate, opts_out->format = COPY_FORMAT_CSV; else if (strcmp(fmt, "binary") == 0) opts_out->format = COPY_FORMAT_BINARY; + else if (strcmp(fmt, "json") == 0) + opts_out->format = COPY_FORMAT_JSON; else ereport(ERROR, (errcode(ERRCODE_INVALID_PARAMETER_VALUE), @@ -756,21 +758,32 @@ ProcessCopyOptions(ParseState *pstate, * Check for incompatible options (must do these three before inserting * defaults) */ - if (opts_out->format == COPY_FORMAT_BINARY && opts_out->delim) + if (opts_out->delim && + (opts_out->format == COPY_FORMAT_BINARY || + opts_out->format == COPY_FORMAT_JSON)) ereport(ERROR, - (errcode(ERRCODE_SYNTAX_ERROR), - /*- translator: %s is the name of a COPY option, e.g. ON_ERROR */ - errmsg("cannot specify %s in BINARY mode", "DELIMITER"))); + errcode(ERRCODE_SYNTAX_ERROR), + opts_out->format == COPY_FORMAT_BINARY + ? errmsg("cannot specify %s in BINARY mode", "DELIMITER") + : errmsg("cannot specify %s in JSON mode", "DELIMITER")); - if (opts_out->format == COPY_FORMAT_BINARY && opts_out->null_print) + if (opts_out->null_print && + (opts_out->format == COPY_FORMAT_BINARY || + opts_out->format == COPY_FORMAT_JSON)) ereport(ERROR, - (errcode(ERRCODE_SYNTAX_ERROR), - errmsg("cannot specify %s in BINARY mode", "NULL"))); + errcode(ERRCODE_SYNTAX_ERROR), + opts_out->format == COPY_FORMAT_BINARY + ? errmsg("cannot specify %s in BINARY mode", "NULL") + : errmsg("cannot specify %s in JSON mode", "NULL")); - if (opts_out->format == COPY_FORMAT_BINARY && opts_out->default_print) + if (opts_out->default_print && + (opts_out->format == COPY_FORMAT_BINARY || + opts_out->format == COPY_FORMAT_JSON)) ereport(ERROR, - (errcode(ERRCODE_SYNTAX_ERROR), - errmsg("cannot specify %s in BINARY mode", "DEFAULT"))); + errcode(ERRCODE_SYNTAX_ERROR), + opts_out->format == COPY_FORMAT_BINARY + ? errmsg("cannot specify %s in BINARY mode", "DEFAULT") + : errmsg("cannot specify %s in JSON mode", "DEFAULT")); /* Set defaults for omitted options */ if (!opts_out->delim) @@ -836,11 +849,15 @@ ProcessCopyOptions(ParseState *pstate, errmsg("COPY delimiter cannot be \"%s\"", opts_out->delim))); /* Check header */ - if (opts_out->format == COPY_FORMAT_BINARY && opts_out->header_line != COPY_HEADER_FALSE) + if (opts_out->header_line != COPY_HEADER_FALSE && + (opts_out->format == COPY_FORMAT_BINARY || + opts_out->format == COPY_FORMAT_JSON)) ereport(ERROR, - (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), + errcode(ERRCODE_FEATURE_NOT_SUPPORTED), /*- translator: %s is the name of a COPY option, e.g. ON_ERROR */ - errmsg("cannot specify %s in BINARY mode", "HEADER"))); + opts_out->format == COPY_FORMAT_BINARY + ? errmsg("cannot specify %s in BINARY mode", "HEADER") + : errmsg("cannot specify %s in JSON mode", "HEADER")); /* Check quote */ if (opts_out->format != COPY_FORMAT_CSV && opts_out->quote != NULL) @@ -944,6 +961,12 @@ ProcessCopyOptions(ParseState *pstate, errmsg("COPY %s cannot be used with %s", "FREEZE", "COPY TO"))); + /* Check json format */ + if (opts_out->format == COPY_FORMAT_JSON && is_from) + ereport(ERROR, + errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("COPY %s mode cannot be used with %s", "JSON", "COPY FROM")); + if (opts_out->default_print) { if (!is_from) diff --git a/src/backend/commands/copyto.c b/src/backend/commands/copyto.c index 0325a16f82a..96605079eeb 100644 --- a/src/backend/commands/copyto.c +++ b/src/backend/commands/copyto.c @@ -26,6 +26,7 @@ #include "executor/execdesc.h" #include "executor/executor.h" #include "executor/tuptable.h" +#include "funcapi.h" #include "libpq/libpq.h" #include "libpq/pqformat.h" #include "mb/pg_wchar.h" @@ -33,6 +34,7 @@ #include "pgstat.h" #include "storage/fd.h" #include "tcop/tcopprot.h" +#include "utils/json.h" #include "utils/lsyscache.h" #include "utils/memutils.h" #include "utils/rel.h" @@ -84,6 +86,11 @@ typedef struct CopyToStateData List *attnumlist; /* integer list of attnums to copy */ char *filename; /* filename, or NULL for STDOUT */ bool is_program; /* is 'filename' a program to popen? */ + + /* JSON format state */ + bool json_tupledesc_ready; /* TupleDesc setup done for JSON */ + StringInfoData json_buf; /* reusable buffer for JSON output */ + copy_data_dest_cb data_dest_cb; /* function for writing data */ CopyFormatOptions opts; @@ -130,6 +137,7 @@ static void CopyToCSVOneRow(CopyToState cstate, TupleTableSlot *slot); static void CopyToTextLikeOneRow(CopyToState cstate, TupleTableSlot *slot, bool is_csv); static void CopyToTextLikeEnd(CopyToState cstate); +static void CopyToJsonOneRow(CopyToState cstate, TupleTableSlot *slot); static void CopyToBinaryStart(CopyToState cstate, TupleDesc tupDesc); static void CopyToBinaryOutFunc(CopyToState cstate, Oid atttypid, FmgrInfo *finfo); static void CopyToBinaryOneRow(CopyToState cstate, TupleTableSlot *slot); @@ -149,7 +157,7 @@ static void CopySendInt16(CopyToState cstate, int16 val); /* * COPY TO routines for built-in formats. * - * CSV and text formats share the same TextLike routines except for the + * CSV, text and json formats share the same TextLike routines except for the * one-row callback. */ @@ -169,6 +177,14 @@ static const CopyToRoutine CopyToRoutineCSV = { .CopyToEnd = CopyToTextLikeEnd, }; +/* json format */ +static const CopyToRoutine CopyToRoutineJson = { + .CopyToStart = CopyToTextLikeStart, + .CopyToOutFunc = CopyToTextLikeOutFunc, + .CopyToOneRow = CopyToJsonOneRow, + .CopyToEnd = CopyToTextLikeEnd, +}; + /* binary format */ static const CopyToRoutine CopyToRoutineBinary = { .CopyToStart = CopyToBinaryStart, @@ -185,12 +201,14 @@ CopyToGetRoutine(const CopyFormatOptions *opts) return &CopyToRoutineCSV; else if (opts->format == COPY_FORMAT_BINARY) return &CopyToRoutineBinary; + else if (opts->format == COPY_FORMAT_JSON) + return &CopyToRoutineJson; /* default is text */ return &CopyToRoutineText; } -/* Implementation of the start callback for text and CSV formats */ +/* Implementation of the start callback for text, CSV, and json formats */ static void CopyToTextLikeStart(CopyToState cstate, TupleDesc tupDesc) { @@ -209,6 +227,8 @@ CopyToTextLikeStart(CopyToState cstate, TupleDesc tupDesc) ListCell *cur; bool hdr_delim = false; + Assert(cstate->opts.format != COPY_FORMAT_JSON); + foreach(cur, cstate->attnumlist) { int attnum = lfirst_int(cur); @@ -228,10 +248,21 @@ CopyToTextLikeStart(CopyToState cstate, TupleDesc tupDesc) CopySendTextLikeEndOfRow(cstate); } + + /* JSON-specific initialization */ + if (cstate->opts.format == COPY_FORMAT_JSON) + { + MemoryContext oldcxt; + + /* Allocate reusable JSON output buffer in long-lived context */ + oldcxt = MemoryContextSwitchTo(cstate->copycontext); + initStringInfo(&cstate->json_buf); + MemoryContextSwitchTo(oldcxt); + } } /* - * Implementation of the outfunc callback for text and CSV formats. Assign + * Implementation of the outfunc callback for text, CSV, and json formats. Assign * the output function data to the given *finfo. */ static void @@ -304,13 +335,47 @@ CopyToTextLikeOneRow(CopyToState cstate, CopySendTextLikeEndOfRow(cstate); } -/* Implementation of the end callback for text and CSV formats */ +/* Implementation of the end callback for text, CSV, and json formats */ static void CopyToTextLikeEnd(CopyToState cstate) { /* Nothing to do here */ } +/* Implementation of per-row callback for json format */ +static void +CopyToJsonOneRow(CopyToState cstate, TupleTableSlot *slot) +{ + Datum rowdata; + + /* + * For query-based COPY, copy the query's TupleDesc attributes into the + * slot's TupleDesc once. BlessTupleDesc registers the RECORDOID + * descriptor so that lookup_rowtype_tupdesc inside composite_to_json can + * find it. + */ + if (!cstate->rel && !cstate->json_tupledesc_ready) + { + memcpy(TupleDescAttr(slot->tts_tupleDescriptor, 0), + TupleDescAttr(cstate->queryDesc->tupDesc, 0), + cstate->queryDesc->tupDesc->natts * sizeof(FormData_pg_attribute)); + + for (int i = 0; i < cstate->queryDesc->tupDesc->natts; i++) + populate_compact_attribute(slot->tts_tupleDescriptor, i); + + BlessTupleDesc(slot->tts_tupleDescriptor); + cstate->json_tupledesc_ready = true; + } + + rowdata = ExecFetchSlotHeapTupleDatum(slot); + resetStringInfo(&cstate->json_buf); + composite_to_json(rowdata, &cstate->json_buf, false); + + CopySendData(cstate, cstate->json_buf.data, cstate->json_buf.len); + + CopySendTextLikeEndOfRow(cstate); +} + /* * Implementation of the start callback for binary format. Send a header * for a binary copy. @@ -402,9 +467,23 @@ SendCopyBegin(CopyToState cstate) pq_beginmessage(&buf, PqMsg_CopyOutResponse); pq_sendbyte(&buf, format); /* overall format */ - pq_sendint16(&buf, natts); - for (i = 0; i < natts; i++) - pq_sendint16(&buf, format); /* per-column formats */ + if (cstate->opts.format != COPY_FORMAT_JSON) + { + pq_sendint16(&buf, natts); + for (i = 0; i < natts; i++) + pq_sendint16(&buf, format); /* per-column formats */ + } + else + { + /* + * For JSON format, report one text-format column. Each CopyData + * message contains one complete JSON object, not individual column + * values, so the per-column count is always 1. + */ + pq_sendint16(&buf, 1); + pq_sendint16(&buf, 0); + } + pq_endmessage(&buf); cstate->copy_dest = COPY_FRONTEND; } @@ -506,7 +585,7 @@ CopySendEndOfRow(CopyToState cstate) } /* - * Wrapper function of CopySendEndOfRow for text and CSV formats. Sends the + * Wrapper function of CopySendEndOfRow for text, CSV, and json formats. Sends the * line termination and do common appropriate things for the end of row. */ static inline void @@ -890,6 +969,12 @@ BeginCopyTo(ParseState *pstate, /* Generate or convert list of attributes to process */ cstate->attnumlist = CopyGetAttnums(tupDesc, cstate->rel, attnamelist); + /* JSON outputs whole rows; a column list doesn't make sense */ + if (cstate->opts.format == COPY_FORMAT_JSON && attnamelist != NIL) + ereport(ERROR, + (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), + errmsg("column selection is not supported in JSON mode"))); + num_phys_attrs = tupDesc->natts; /* Convert FORCE_QUOTE name list to per-column flags, check validity */ diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y index c567252acc4..db98f2d91bf 100644 --- a/src/backend/parser/gram.y +++ b/src/backend/parser/gram.y @@ -3609,6 +3609,10 @@ copy_opt_item: { $$ = makeDefElem("format", (Node *) makeString("csv"), @1); } + | JSON + { + $$ = makeDefElem("format", (Node *) makeString("json"), @1); + } | HEADER_P { $$ = makeDefElem("header", (Node *) makeBoolean(true), @1); @@ -3691,6 +3695,10 @@ copy_generic_opt_elem: { $$ = makeDefElem($1, $2, @1); } + | FORMAT_LA copy_generic_opt_arg + { + $$ = makeDefElem("format", $2, @1); + } ; copy_generic_opt_arg: diff --git a/src/backend/utils/adt/json.c b/src/backend/utils/adt/json.c index 0b161398465..f609d7b9417 100644 --- a/src/backend/utils/adt/json.c +++ b/src/backend/utils/adt/json.c @@ -86,8 +86,6 @@ typedef struct JsonAggState JsonUniqueBuilderState unique_check; } JsonAggState; -static void composite_to_json(Datum composite, StringInfo result, - bool use_line_feeds); static void array_dim_to_json(StringInfo result, int dim, int ndims, int *dims, const Datum *vals, const bool *nulls, int *valcount, JsonTypeCategory tcategory, Oid outfuncoid, @@ -517,8 +515,9 @@ array_to_json_internal(Datum array, StringInfo result, bool use_line_feeds) /* * Turn a composite / record into JSON. + * Exported so COPY TO can use it. */ -static void +void composite_to_json(Datum composite, StringInfo result, bool use_line_feeds) { HeapTupleHeader td; diff --git a/src/bin/psql/tab-complete.in.c b/src/bin/psql/tab-complete.in.c index 905c076763c..d257837b0c5 100644 --- a/src/bin/psql/tab-complete.in.c +++ b/src/bin/psql/tab-complete.in.c @@ -3425,7 +3425,7 @@ match_previous_words(int pattern_id, /* Complete COPY FROM|TO filename WITH (FORMAT */ else if (TailMatches("FORMAT")) - COMPLETE_WITH("binary", "csv", "text"); + COMPLETE_WITH("binary", "csv", "text", "json"); /* Complete COPY FROM|TO filename WITH (FREEZE */ else if (TailMatches("FREEZE")) diff --git a/src/include/commands/copy.h b/src/include/commands/copy.h index 2430fb0b2e5..2b5bef6738e 100644 --- a/src/include/commands/copy.h +++ b/src/include/commands/copy.h @@ -57,6 +57,7 @@ typedef enum CopyFormat COPY_FORMAT_TEXT = 0, COPY_FORMAT_BINARY, COPY_FORMAT_CSV, + COPY_FORMAT_JSON, } CopyFormat; /* diff --git a/src/include/utils/json.h b/src/include/utils/json.h index f8cc52b1e78..2f4be40518d 100644 --- a/src/include/utils/json.h +++ b/src/include/utils/json.h @@ -17,6 +17,8 @@ #include "lib/stringinfo.h" /* functions in json.c */ +extern void composite_to_json(Datum composite, StringInfo result, + bool use_line_feeds); extern void escape_json(StringInfo buf, const char *str); extern void escape_json_with_len(StringInfo buf, const char *str, int len); extern void escape_json_text(StringInfo buf, const text *txt); diff --git a/src/test/regress/expected/copy.out b/src/test/regress/expected/copy.out index d0d563e0fa8..4ea658a45de 100644 --- a/src/test/regress/expected/copy.out +++ b/src/test/regress/expected/copy.out @@ -73,6 +73,84 @@ copy copytest3 to stdout csv header; c1,"col with , comma","col with "" quote" 1,a,1 2,b,2 +--- test copying in JSON mode with various styles +copy copytest to stdout json; +{"style":"DOS","test":"abc\r\ndef","filler":1} +{"style":"Unix","test":"abc\ndef","filler":2} +{"style":"Mac","test":"abc\rdef","filler":3} +{"style":"esc\\ape","test":"a\\r\\\r\\\n\\nb","filler":4} +copy copytest to stdout (format json); +{"style":"DOS","test":"abc\r\ndef","filler":1} +{"style":"Unix","test":"abc\ndef","filler":2} +{"style":"Mac","test":"abc\rdef","filler":3} +{"style":"esc\\ape","test":"a\\r\\\r\\\n\\nb","filler":4} +-- all of the following should yield error +copy copytest to stdout (format json, delimiter '|'); +ERROR: cannot specify DELIMITER in JSON mode +copy copytest to stdout (format json, null '\N'); +ERROR: cannot specify NULL in JSON mode +copy copytest to stdout (format json, default '|'); +ERROR: cannot specify DEFAULT in JSON mode +copy copytest to stdout (format json, header); +ERROR: cannot specify HEADER in JSON mode +copy copytest to stdout (format json, header 1); +ERROR: cannot specify HEADER in JSON mode +copy copytest to stdout (format json, quote '"'); +ERROR: COPY QUOTE requires CSV mode +copy copytest to stdout (format json, escape '"'); +ERROR: COPY ESCAPE requires CSV mode +copy copytest to stdout (format json, force_quote *); +ERROR: COPY FORCE_QUOTE requires CSV mode +copy copytest to stdout (format json, force_not_null *); +ERROR: COPY FORCE_NOT_NULL requires CSV mode +copy copytest to stdout (format json, force_null *); +ERROR: COPY FORCE_NULL requires CSV mode +copy copytest to stdout (format json, on_error ignore); +ERROR: COPY ON_ERROR cannot be used with COPY TO +LINE 1: copy copytest to stdout (format json, on_error ignore); + ^ +copy copytest from stdin(format json); +ERROR: COPY JSON mode cannot be used with COPY FROM +copy copytest (style) to stdout (format json); +ERROR: column selection is not supported in JSON mode +-- all of the above should yield error +-- embedded escaped characters +create temp table copyjsontest ( + id bigserial, + f1 text, + f2 timestamptz); +insert into copyjsontest + select g.i, + CASE WHEN g.i % 2 = 0 THEN + 'line with '' in it: ' || g.i::text + ELSE + 'line with " in it: ' || g.i::text + END, + 'Mon Feb 10 17:32:01 1997 PST' + from generate_series(1,5) as g(i); +insert into copyjsontest (f1) values +(E'aaa\"bbb'::text), +(E'aaa\\bbb'::text), +(E'aaa\/bbb'::text), +(E'aaa\bbbb'::text), +(E'aaa\fbbb'::text), +(E'aaa\nbbb'::text), +(E'aaa\rbbb'::text), +(E'aaa\tbbb'::text); +copy copyjsontest to stdout json; +{"id":1,"f1":"line with \" in it: 1","f2":"1997-02-10T17:32:01-08:00"} +{"id":2,"f1":"line with ' in it: 2","f2":"1997-02-10T17:32:01-08:00"} +{"id":3,"f1":"line with \" in it: 3","f2":"1997-02-10T17:32:01-08:00"} +{"id":4,"f1":"line with ' in it: 4","f2":"1997-02-10T17:32:01-08:00"} +{"id":5,"f1":"line with \" in it: 5","f2":"1997-02-10T17:32:01-08:00"} +{"id":1,"f1":"aaa\"bbb","f2":null} +{"id":2,"f1":"aaa\\bbb","f2":null} +{"id":3,"f1":"aaa/bbb","f2":null} +{"id":4,"f1":"aaa\bbbb","f2":null} +{"id":5,"f1":"aaa\fbbb","f2":null} +{"id":6,"f1":"aaa\nbbb","f2":null} +{"id":7,"f1":"aaa\rbbb","f2":null} +{"id":8,"f1":"aaa\tbbb","f2":null} create temp table copytest4 ( c1 int, "colname with tab: " text); diff --git a/src/test/regress/sql/copy.sql b/src/test/regress/sql/copy.sql index 65cbdaf7f3e..c558eba202a 100644 --- a/src/test/regress/sql/copy.sql +++ b/src/test/regress/sql/copy.sql @@ -82,6 +82,54 @@ this is just a line full of junk that would error out if parsed copy copytest3 to stdout csv header; +--- test copying in JSON mode with various styles +copy copytest to stdout json; +copy copytest to stdout (format json); + +-- all of the following should yield error +copy copytest to stdout (format json, delimiter '|'); +copy copytest to stdout (format json, null '\N'); +copy copytest to stdout (format json, default '|'); +copy copytest to stdout (format json, header); +copy copytest to stdout (format json, header 1); +copy copytest to stdout (format json, quote '"'); +copy copytest to stdout (format json, escape '"'); +copy copytest to stdout (format json, force_quote *); +copy copytest to stdout (format json, force_not_null *); +copy copytest to stdout (format json, force_null *); +copy copytest to stdout (format json, on_error ignore); +copy copytest from stdin(format json); +copy copytest (style) to stdout (format json); +-- all of the above should yield error + +-- embedded escaped characters +create temp table copyjsontest ( + id bigserial, + f1 text, + f2 timestamptz); + +insert into copyjsontest + select g.i, + CASE WHEN g.i % 2 = 0 THEN + 'line with '' in it: ' || g.i::text + ELSE + 'line with " in it: ' || g.i::text + END, + 'Mon Feb 10 17:32:01 1997 PST' + from generate_series(1,5) as g(i); + +insert into copyjsontest (f1) values +(E'aaa\"bbb'::text), +(E'aaa\\bbb'::text), +(E'aaa\/bbb'::text), +(E'aaa\bbbb'::text), +(E'aaa\fbbb'::text), +(E'aaa\nbbb'::text), +(E'aaa\rbbb'::text), +(E'aaa\tbbb'::text); + +copy copyjsontest to stdout json; + create temp table copytest4 ( c1 int, "colname with tab: " text); -- 2.43.0