From de3600452b61d1bc3967e9e37e86db8956c8f577 Mon Sep 17 00:00:00 2001 From: Amit Langote Date: Thu, 4 Apr 2024 19:57:08 +0900 Subject: Add basic JSON_TABLE() functionality MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit JSON_TABLE() allows JSON data to be converted into a relational view and thus used, for example, in a FROM clause, like other tabular data. Data to show in the view is selected from a source JSON object using a JSON path expression to get a sequence of JSON objects that's called a "row pattern", which becomes the source to compute the SQL/JSON values that populate the view's output columns. Column values themselves are computed using JSON path expressions applied to each of the JSON objects comprising the "row pattern", for which the SQL/JSON query functions added in 6185c9737cf4 are used. To implement JSON_TABLE() as a table function, this augments the TableFunc and TableFuncScanState nodes that are currently used to support XMLTABLE() with some JSON_TABLE()-specific fields. Note that the JSON_TABLE() spec includes NESTED COLUMNS and PLAN clauses, which are required to provide more flexibility to extract data out of nested JSON objects, but they are not implemented here to keep this commit of manageable size. Author: Nikita Glukhov Author: Teodor Sigaev Author: Oleg Bartunov Author: Alexander Korotkov Author: Andrew Dunstan Author: Amit Langote Author: Jian He Reviewers have included (in no particular order): Andres Freund, Alexander Korotkov, Pavel Stehule, Andrew Alsup, Erik Rijkers, Zihong Yu, Himanshu Upadhyaya, Daniel Gustafsson, Justin Pryzby, Álvaro Herrera, Jian He Discussion: https://postgr.es/m/cd0bb935-0158-78a7-08b5-904886deac4b@postgrespro.ru Discussion: https://postgr.es/m/20220616233130.rparivafipt6doj3@alap3.anarazel.de Discussion: https://postgr.es/m/abd9b83b-aa66-f230-3d6d-734817f0995d%40postgresql.org Discussion: https://postgr.es/m/CA+HiwqE4XTdfb1nW=Ojoy_tQSRhYt-q_kb6i5d4xcKyrLC1Nbg@mail.gmail.com --- .../ecpg/test/expected/sql-sqljson_jsontable.c | 143 +++++++++++++++++++++ 1 file changed, 143 insertions(+) create mode 100644 src/interfaces/ecpg/test/expected/sql-sqljson_jsontable.c (limited to 'src/interfaces/ecpg/test/expected/sql-sqljson_jsontable.c') diff --git a/src/interfaces/ecpg/test/expected/sql-sqljson_jsontable.c b/src/interfaces/ecpg/test/expected/sql-sqljson_jsontable.c new file mode 100644 index 00000000000..42a1b176e72 --- /dev/null +++ b/src/interfaces/ecpg/test/expected/sql-sqljson_jsontable.c @@ -0,0 +1,143 @@ +/* Processed by ecpg (regression mode) */ +/* These include files are added by the preprocessor */ +#include +#include +#include +/* End of automatic include section */ +#define ECPGdebug(X,Y) ECPGdebug((X)+100,(Y)) + +#line 1 "sqljson_jsontable.pgc" +#include + + +#line 1 "sqlca.h" +#ifndef POSTGRES_SQLCA_H +#define POSTGRES_SQLCA_H + +#ifndef PGDLLIMPORT +#if defined(WIN32) || defined(__CYGWIN__) +#define PGDLLIMPORT __declspec (dllimport) +#else +#define PGDLLIMPORT +#endif /* __CYGWIN__ */ +#endif /* PGDLLIMPORT */ + +#define SQLERRMC_LEN 150 + +#ifdef __cplusplus +extern "C" +{ +#endif + +struct sqlca_t +{ + char sqlcaid[8]; + long sqlabc; + long sqlcode; + struct + { + int sqlerrml; + char sqlerrmc[SQLERRMC_LEN]; + } sqlerrm; + char sqlerrp[8]; + long sqlerrd[6]; + /* Element 0: empty */ + /* 1: OID of processed tuple if applicable */ + /* 2: number of rows processed */ + /* after an INSERT, UPDATE or */ + /* DELETE statement */ + /* 3: empty */ + /* 4: empty */ + /* 5: empty */ + char sqlwarn[8]; + /* Element 0: set to 'W' if at least one other is 'W' */ + /* 1: if 'W' at least one character string */ + /* value was truncated when it was */ + /* stored into a host variable. */ + + /* + * 2: if 'W' a (hopefully) non-fatal notice occurred + */ /* 3: empty */ + /* 4: empty */ + /* 5: empty */ + /* 6: empty */ + /* 7: empty */ + + char sqlstate[5]; +}; + +struct sqlca_t *ECPGget_sqlca(void); + +#ifndef POSTGRES_ECPG_INTERNAL +#define sqlca (*ECPGget_sqlca()) +#endif + +#ifdef __cplusplus +} +#endif + +#endif + +#line 3 "sqljson_jsontable.pgc" + + +#line 1 "regression.h" + + + + + + +#line 4 "sqljson_jsontable.pgc" + + +/* exec sql whenever sqlerror sqlprint ; */ +#line 6 "sqljson_jsontable.pgc" + + +int +main () +{ +/* exec sql begin declare section */ + + +#line 12 "sqljson_jsontable.pgc" + int foo ; +/* exec sql end declare section */ +#line 13 "sqljson_jsontable.pgc" + + + ECPGdebug (1, stderr); + + { ECPGconnect(__LINE__, 0, "ecpg1_regression" , NULL, NULL , NULL, 0); +#line 17 "sqljson_jsontable.pgc" + +if (sqlca.sqlcode < 0) sqlprint();} +#line 17 "sqljson_jsontable.pgc" + + { ECPGsetcommit(__LINE__, "on", NULL); +#line 18 "sqljson_jsontable.pgc" + +if (sqlca.sqlcode < 0) sqlprint();} +#line 18 "sqljson_jsontable.pgc" + + + { ECPGdo(__LINE__, 0, 1, NULL, 0, ECPGst_normal, "select foo from json_table ( jsonb '[{\"foo\":1}]' , '$[*]' as p0 columns ( foo int ) ) jt ( foo )", ECPGt_EOIT, + ECPGt_int,&(foo),(long)1,(long)1,sizeof(int), + ECPGt_NO_INDICATOR, NULL , 0L, 0L, 0L, ECPGt_EORT); +#line 23 "sqljson_jsontable.pgc" + +if (sqlca.sqlcode < 0) sqlprint();} +#line 23 "sqljson_jsontable.pgc" + + printf("Found foo=%d\n", foo); + + { ECPGdisconnect(__LINE__, "CURRENT"); +#line 26 "sqljson_jsontable.pgc" + +if (sqlca.sqlcode < 0) sqlprint();} +#line 26 "sqljson_jsontable.pgc" + + + return 0; +} -- cgit v1.2.3