SQL/JSON: add standard JSON constructor functions

This commit introduces the SQL/JSON standard-conforming constructors for
JSON types:

JSON_ARRAY()
JSON_ARRAYAGG()
JSON_OBJECT()
JSON_OBJECTAGG()

Most of the functionality was already present in PostgreSQL-specific
functions, but these include some new functionality such as the ability
to skip or include NULL values, and to allow duplicate keys or throw
error when they are found, as well as the standard specified syntax to
specify output type and format.

Author: Nikita Glukhov <[email protected]>
Author: Teodor Sigaev <[email protected]>
Author: Oleg Bartunov <[email protected]>
Author: Alexander Korotkov <[email protected]>
Author: Amit Langote <[email protected]>

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.

Discussion: https://postgr.es/m/CAF4Au4w2x-5LTnN_bxky-mq4=WOqsGsxSpENCzHRAzSnEd8+WQ@mail.gmail.com
Discussion: https://postgr.es/m/[email protected]
Discussion: https://postgr.es/m/[email protected]
Discussion: https://postgr.es/m/abd9b83b-aa66-f230-3d6d-734817f0995d%40postgresql.org

1 files changed, 203 insertions, 0 deletions

diff --git a/src/interfaces/ecpg/test/expected/sql-sqljson.c b/src/interfaces/ecpg/test/expected/sql-sqljson.c
new file mode 100644
index 00000000000..64784542ed6
--- /dev/null
+++ b/src/interfaces/ecpg/test/expected/sql-sqljson.c
@@ -0,0 +1,203 @@
+/* Processed by ecpg (regression mode) */
+/* These include files are added by the preprocessor */
+#include <ecpglib.h>
+#include <ecpgerrno.h>
+#include <sqlca.h>
+/* End of automatic include section */
+#define ECPGdebug(X,Y) ECPGdebug((X)+100,(Y))
+
+#line 1 "sqljson.pgc"
+#include <stdio.h>
+
+
+#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.pgc"
+
+
+#line 1 "regression.h"
+
+
+
+
+
+
+#line 4 "sqljson.pgc"
+
+
+/* exec sql whenever sqlerror  sqlprint ; */
+#line 6 "sqljson.pgc"
+
+
+int
+main ()
+{
+/* exec sql begin declare section */
+   
+
+#line 12 "sqljson.pgc"
+ char json [ 1024 ] ;
+/* exec sql end declare section */
+#line 13 "sqljson.pgc"
+
+
+  ECPGdebug (1, stderr);
+
+  { ECPGconnect(__LINE__, 0, "ecpg1_regression" , NULL, NULL , NULL, 0); 
+#line 17 "sqljson.pgc"
+
+if (sqlca.sqlcode < 0) sqlprint();}
+#line 17 "sqljson.pgc"
+
+  { ECPGsetcommit(__LINE__, "on", NULL);
+#line 18 "sqljson.pgc"
+
+if (sqlca.sqlcode < 0) sqlprint();}
+#line 18 "sqljson.pgc"
+
+
+  { ECPGdo(__LINE__, 0, 1, NULL, 0, ECPGst_normal, "select json_object ( returning text )", ECPGt_EOIT, 
+	ECPGt_char,(json),(long)1024,(long)1,(1024)*sizeof(char), 
+	ECPGt_NO_INDICATOR, NULL , 0L, 0L, 0L, ECPGt_EORT);
+#line 20 "sqljson.pgc"
+
+if (sqlca.sqlcode < 0) sqlprint();}
+#line 20 "sqljson.pgc"
+
+  printf("Found json=%s\n", json);
+
+  { ECPGdo(__LINE__, 0, 1, NULL, 0, ECPGst_normal, "select json_object ( returning text format json )", ECPGt_EOIT, 
+	ECPGt_char,(json),(long)1024,(long)1,(1024)*sizeof(char), 
+	ECPGt_NO_INDICATOR, NULL , 0L, 0L, 0L, ECPGt_EORT);
+#line 23 "sqljson.pgc"
+
+if (sqlca.sqlcode < 0) sqlprint();}
+#line 23 "sqljson.pgc"
+
+  printf("Found json=%s\n", json);
+
+  { ECPGdo(__LINE__, 0, 1, NULL, 0, ECPGst_normal, "select json_array ( returning jsonb )", ECPGt_EOIT, 
+	ECPGt_char,(json),(long)1024,(long)1,(1024)*sizeof(char), 
+	ECPGt_NO_INDICATOR, NULL , 0L, 0L, 0L, ECPGt_EORT);
+#line 26 "sqljson.pgc"
+
+if (sqlca.sqlcode < 0) sqlprint();}
+#line 26 "sqljson.pgc"
+
+  printf("Found json=%s\n", json);
+
+  { ECPGdo(__LINE__, 0, 1, NULL, 0, ECPGst_normal, "select json_array ( returning jsonb format json )", ECPGt_EOIT, 
+	ECPGt_char,(json),(long)1024,(long)1,(1024)*sizeof(char), 
+	ECPGt_NO_INDICATOR, NULL , 0L, 0L, 0L, ECPGt_EORT);
+#line 29 "sqljson.pgc"
+
+if (sqlca.sqlcode < 0) sqlprint();}
+#line 29 "sqljson.pgc"
+
+  printf("Found json=%s\n", json);
+
+  { ECPGdo(__LINE__, 0, 1, NULL, 0, ECPGst_normal, "select json_object ( 1 : 1 , '1' : null with unique )", ECPGt_EOIT, 
+	ECPGt_char,(json),(long)1024,(long)1,(1024)*sizeof(char), 
+	ECPGt_NO_INDICATOR, NULL , 0L, 0L, 0L, ECPGt_EORT);
+#line 32 "sqljson.pgc"
+
+if (sqlca.sqlcode < 0) sqlprint();}
+#line 32 "sqljson.pgc"
+
+  // error
+
+  { ECPGdo(__LINE__, 0, 1, NULL, 0, ECPGst_normal, "select json_object ( 1 : 1 , '2' : null , 1 : '2' absent on null without unique keys )", ECPGt_EOIT, 
+	ECPGt_char,(json),(long)1024,(long)1,(1024)*sizeof(char), 
+	ECPGt_NO_INDICATOR, NULL , 0L, 0L, 0L, ECPGt_EORT);
+#line 35 "sqljson.pgc"
+
+if (sqlca.sqlcode < 0) sqlprint();}
+#line 35 "sqljson.pgc"
+
+  printf("Found json=%s\n", json);
+
+  { ECPGdo(__LINE__, 0, 1, NULL, 0, ECPGst_normal, "select json_object ( 1 : 1 , '2' : null absent on null without unique returning jsonb )", ECPGt_EOIT, 
+	ECPGt_char,(json),(long)1024,(long)1,(1024)*sizeof(char), 
+	ECPGt_NO_INDICATOR, NULL , 0L, 0L, 0L, ECPGt_EORT);
+#line 38 "sqljson.pgc"
+
+if (sqlca.sqlcode < 0) sqlprint();}
+#line 38 "sqljson.pgc"
+
+  printf("Found json=%s\n", json);
+
+  { ECPGdisconnect(__LINE__, "CURRENT");
+#line 41 "sqljson.pgc"
+
+if (sqlca.sqlcode < 0) sqlprint();}
+#line 41 "sqljson.pgc"
+
+
+  return 0;
+}