After answering hundreds of calls for orders, Wang Zhongkui said he knows what people need most under lockdown－whether it's bananas, diapers, baby formula or simply a charging cable.

The 41-year-old is general manager of an RT-Mart supermarket in Nanhui district, Shanghai, part of the region east of Huangpu River that has been under lockdown since March 28 due to a surge of COVID-19 infections totaling 250,000 by Wednesday.

Wang's personal phone number was printed on a notice of supply, which was intended for community contacts only, but as the notice circulated among residents on April 1, Wang's phone started to ring nonstop.

"I picked up the first call at 7 am on April 1, then one call after another, I answered around 100 calls every day in the coming days," he said.

Wang has worked in supermarkets for 17 years, and had much experience handling the peak shopping seasons as well as during the pandemic, but this time was unusual.

"People started ordering things right way when I picked up the phone," he said. "Some asked for meat, eggs and milk. Some ordered vegetables. Some wanted diapers."

While young people called in for instant noodles as they don't know how to cook, an elderly woman asked specially for bananas, which were essential to ease her constipation, Wang added.

"One mother, whose baby was only 20 days old, called in for milk formula powder," he said. "I could hear the desperation in her voice. We sent her the milk powder at once."

Later, Wang set up a special team responding to needs for babies despite a severe shortage of manpower. The supermarket has around 260 employees, but many were under lockdown in their homes. Only around 100 chose to stay and live in the supermarket, sleeping on the floor at night.

The store is also short of vehicles for deliveries.

It has only two: one owned by the supermarket and the other belonging to a local volunteer, Tang Feng, who had offered to help with deliveries.

"In the busiest days, they set out at 4 am and came back after 11 pm," he said. "We have to prioritize community orders as more people are waiting.

"But some individual's needs were too urgent to be turned down," Wang said.

"The items they need might look so trivial, but they can't do without them."

Wang remembered a young woman who called for a charging cable for her phone, because her battery was running low and it was her only way to stay connected with the outside world.

"This was not in our plan, but we managed to get her the cable," he said.

There were orders that were also claimed to be "urgent" yet never taken.

"Many asked for cigarettes and were willing to pay extra," Wang said. "But sorry, we don't take such orders in a time like this."

Wang did offer his advice to some smokers from time to time, though. "One had called in for a lighter," Wang said with a chuckle. "After he finished, I asked, 'don't you have a gas stove at home?' The request was then withdrawn."

Since April 9, the supermarket chain has sent 600 staff from Jiangsu, Zhejiang and Anhui provinces to Shanghai, and Wang had 65 people sorting and bagging orders at his branch on Monday.

Although his personal number has already been removed from the notice, there are still people calling him from time to time.

"Now the orders for meat and vegetables are falling but the demand for other daily commodities is rising," Wang said.

However busy he is in the day, Wang, who has been living in the supermarket for more than one month, said there is one video call he doesn't miss each night.

"I call my family every night. I ask my son how he has done with his homework and ask him to play the piano for me," Wang said. "That's the hotline of my own."