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PONot able to retrieve values from Berkeley DB in C
 

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  1. PONot able to retrieve values from Berkeley DB in C
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    <p>I have two separate codes, one for inserting the data and one for retrieving the data in Berkeley DB using C. My problem is I am able to see that my data is stored and when I do a db->get immediately after db->put, I see the values. But when I try to do db->get via a separate code, I am having problems, the error I get is db->get: DB_NOTFOUND, when I don't use any delete function. Not sure where the error is</p> <p>Inserting data code: (I pass a string from some other function into it)</p> <pre><code>int db_json(char *json) { typedef struct { char data1[500]; } pearson_record; pearson_record s; int i =0; DB *dbp; DBT key, data; int ret, t_ret; int recno; if ((ret = db_create(&amp;dbp, NULL, 0)) != 0) { fprintf(stderr, "db_create: %s\n", db_strerror(ret)); exit (1); } if ((ret = dbp-&gt;open(dbp, NULL, DATABASE, NULL, DB_BTREE, DB_CREATE, 0664)) != 0) { dbp-&gt;err(dbp, ret, "%s", DATABASE); goto err; } printf("data: %s\n",json); strncpy(s.data1, json, strlen(json)+1); recno = 1; memset(&amp;key, 0, sizeof(key)); memset(&amp;data, 0, sizeof(data)); key.data = &amp;recno; key.size = sizeof(recno); data.data = &amp;s; data.size = sizeof(s); if ((ret = dbp-&gt;put(dbp, NULL, &amp;key,&amp;data,0)) == 0) printf("db: %d: key stored.\n", *(int *)key.data); else { dbp-&gt;err(dbp, ret, "DB-&gt;put"); goto err; } err: if ((t_ret = dbp-&gt;close(dbp, 0)) != 0 &amp;&amp; ret == 0) ret = t_ret; return 0; } </code></pre> <p>Retrieving data code:</p> <pre><code>#include &lt;stdio.h&gt; #include &lt;stdlib.h&gt; #include &lt;string.h&gt; #include &lt;json/json.h&gt; #include &lt;curl/curl.h&gt; #include &lt;sys/types.h&gt; #include &lt;db.h&gt; #define DATABASE "mydata.db" int main() { typedef struct { char data1[500]; } pearson_record; pearson_record s; int i =0; DB *dbp; DBT key, data; int ret, t_ret; int recno; if ((ret = db_create(&amp;dbp, NULL, 0)) != 0) { fprintf(stderr, "db_create: %s\n", db_strerror(ret)); exit (1); } if ((ret = dbp-&gt;open(dbp, NULL, DATABASE, NULL, DB_BTREE, DB_CREATE, 0664)) != 0) { dbp-&gt;err(dbp, ret, "%s", DATABASE); goto err; } memset(&amp;key, 0, sizeof(key)); memset(&amp;data, 0, sizeof(data)); pearson_record *ppr; if ((ret = dbp-&gt;get(dbp, NULL, &amp;key, &amp;data, 0)) == 0) { ppr = (pearson_record *) data.data; printf("db: %d: key retrieved: data was %s %d\n", *(int *)key.data, ppr-&gt;data1, data.size); } else { dbp-&gt;err(dbp, ret, "DB-&gt;get"); } goto err; err: if ((t_ret = dbp-&gt;close(dbp, 0)) != 0 &amp;&amp; ret == 0) ret = t_ret; return 0; } </code></pre>
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    1. USVicky
    1. USuser537670
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    1. COI just tided up the formatting of the code blocks for you to make it easier to read. It's really unpleasant code, though: why are you `typedef`ing the same structure twice (within your functions, even) instead of in one header file that you include in both places; and there's no need to use `goto` in this kind of scenario.
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      1. PONot able to retrieve values from Berkeley DB in C
      1. USVicky
    2. COHave you verified that the data is actually written to the database? using the db_dump tool?
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      1. PONot able to retrieve values from Berkeley DB in C
      1. USFerruccio
    3. COyup the data is written
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      1. USuser537670
 

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